Fingerprint reading device

ABSTRACT

A fingerprint reading device that can suppress a position shift of a finger, that includes: a placement portion on which a finger is placed; a reading face; a pair of light sources provided on the placement portion and that irradiate the finger with lights; and a reading unit that captures and reads a fingerprint of the finger in contact with the reading face in accordance with lights scattered in the finger and emitted from a surface of the finger, the pair of light sources are provided on both ends of the reading face that are opposed to each other in a width direction of the placement portion and
         have light guiding parts formed in a front-back direction of the placement portion, respectively, and the light guiding parts are formed so as to extend up to above the ends of the reading face.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 17/131,050 filed on Dec. 22, 2020, which is acontinuation application of U.S. patent application Ser. No. 16/322,194filed on Jan. 31, 2019, which is a National Stage Entry of internationalapplication PCT/JP2018/027237 filed on Jul. 20, 2018, which claims thebenefit of priority from Japanese Patent Application No. 2017-144533filed on Jul. 26, 2017, the disclosures of all of which are incorporatedin their entirety by reference herein.

TECHNICAL FIELD

The present invention relates to a fingerprint reading device.

BACKGROUND ART

Fingerprints have uniqueness and permanence because fingerprints aredifferent among individuals and do not change in their lifetime. Thus,fingerprints have been widely used in the situations where recognitionof an individual is required.

As a device that reads a fingerprint as described above, a device of anoptical type, an electrostatic capacitance type, and the like is known(see, Patent Literatures 1 to 4). For example, in a device of an opticaltype, a fingerprint is captured and read by using a two-dimensionalimage sensor such as a Complementary Metal Oxide Semiconductor (CMOS)image sensor or the like.

Among the optical devices that capture a fingerprint by using an imagesensor, a transmission-type fingerprint input device has been focused on(see Patent Literatures 1 to 3). In a transmission-type fingerprintinput device, a light from a light source is caused to enter a fingerand is scattered therein, and a light exiting from the surface of thefinger is utilized to capture an image of a fingerprint.

CITATION LIST Patent Literature

PTL 1: International Publication No. 2017/047090

PTL 2: International Publication No. 2017/047091

PTL 3: International Publication No. 2017/047092

PTL 4: Japanese Patent Application Laid-Open No. 2005-182474

SUMMARY OF INVENTION Technical Problem

As described above, when a fingerprint is read by each of variousschemes, in general, a finger from which a fingerprint is read is placedon a reading face on a reading sensor supported by the scheme, such asan image sensor, and the fingerprint is then read. In this case, forexample, a relatively soft finger such as a wet finger, a finger with ahigh water-retention capability, a finger of a newborn or an infant maycause a position shift with respect to a sensor face when a finger isplaced on the reading face in a particular manner. Since it is difficultto appropriately read a fingerprint from a finger where a position shiftwith respect to the reading face occurs, it is difficult to acquire ahigh quality fingerprint image that can be utilized for recognition ofan individual or the like.

The present invention intends to provide a fingerprint reading devicethat can suppress a position shift of a finger whose fingerprint is tobe read with respect to a reading face.

Solution to Problem

According to one example aspect of the present invention, provided is afingerprint reading device includes: a placement portion on which afinger is placed; a reading face with which the finger placed on theplacement portion contacts; a pair of light sources that are provided onthe placement portion and irradiate the finger placed on the placementportion with lights; and a reading unit that captures and reads afingerprint of the finger in contact with the reading face in accordancewith lights scattered in the finger and emitted from a surface of thefinger, the pair of light sources are provided on both ends of thereading face that are opposed to each other in a width direction of theplacement portion and have light guiding parts formed in a front-backdirection of the placement portion, respectively, and the light guidingparts are formed so as to extend up to above the ends of the readingface.

Advantageous Effects of Invention

According to the present invention, it is possible to suppress aposition shift of a finger whose fingerprint is to be read with respectto a reading face.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a fingerprint reading systemaccording to a first example embodiment of the present invention.

FIG. 2 is a plan view illustrating a fingerprint reading deviceaccording to the first example embodiment of the present invention.

FIG. 3 is a longitudinal sectional view illustrating the fingerprintreading device according to the first example embodiment of the presentinvention.

FIG. 4 is a transverse sectional view illustrating the fingerprintreading device according to the first example embodiment of the presentinvention.

FIG. 5A is a schematic diagram illustrating an example of a sensor driveunit in the fingerprint reading device according to the first exampleembodiment of the present invention.

FIG. 5B is a schematic diagram illustrating an example of the sensordrive unit in the fingerprint reading device according to the firstexample embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating a view in which a fingerprintof a finger of a subject is read by using the fingerprint reading deviceaccording to the first example embodiment of the present invention.

FIG. 7 is a block diagram illustrating the fingerprint reading deviceaccording to the first example embodiment of the present invention.

FIG. 8 is a block diagram illustrating an image processing apparatusaccording to the first example embodiment of the present invention.

FIG. 9A is a schematic diagram illustrating the operation of thefingerprint reading device according to the first example embodiment ofthe present invention.

FIG. 9B is a schematic diagram illustrating the operation of thefingerprint reading device according to the first example embodiment ofthe present invention.

FIG. 9C is a schematic diagram illustrating the operation of thefingerprint reading device according to the first example embodiment ofthe present invention.

FIG. 10A is a schematic diagram illustrating the principle by whichdeformation of a fingerprint is reduced when the fingerprint is read byusing the fingerprint reading device according to the first exampleembodiment of the present invention.

FIG. 10B is a schematic diagram illustrating the principle by whichdeformation of a fingerprint is reduced when the fingerprint is read byusing the fingerprint reading device according to the first exampleembodiment of the present invention.

FIG. 10C is a schematic diagram illustrating the principle by whichdeformation of a fingerprint is reduced when the fingerprint is read byusing the fingerprint reading device according to the first exampleembodiment of the present invention.

FIG. 11 is a plan view illustrating a fingerprint reading deviceaccording to a second example embodiment of the present invention.

FIG. 12 is a longitudinal sectional view illustrating the fingerprintreading device according to the second example embodiment of the presentinvention.

FIG. 13A is a schematic diagram illustrating the operation of thefingerprint reading device according to the second example embodiment ofthe present invention.

FIG. 13B is a schematic diagram illustrating the operation of thefingerprint reading device according to the second example embodiment ofthe present invention.

FIG. 13C is a schematic diagram illustrating the operation of thefingerprint reading device according to the second example embodiment ofthe present invention.

FIG. 14 is a plan view illustrating a fingerprint reading deviceaccording to a third example embodiment of the present invention.

FIG. 15 is a longitudinal sectional view illustrating the fingerprintreading device according to the third example embodiment of the presentinvention.

FIG. 16A is a schematic diagram illustrating an example of a sensordrive unit in the fingerprint reading device according to the thirdexample embodiment of the present invention.

FIG. 16B is a schematic diagram illustrating an example of the sensordrive unit in the fingerprint reading device according to the thirdexample embodiment of the present invention.

FIG. 17A is a schematic diagram illustrating the operation of thefingerprint reading device according to the third example embodiment ofthe present invention.

FIG. 17B is a schematic diagram illustrating the operation of thefingerprint reading device according to the third example embodiment ofthe present invention.

FIG. 17C is a schematic diagram illustrating the operation of thefingerprint reading device according to the third example embodiment ofthe present invention.

FIG. 18 is a plan view illustrating a fingerprint reading deviceaccording to a fourth example embodiment of the present invention.

FIG. 19 is a plan view illustrating a fingerprint reading deviceaccording to a fifth example embodiment of the present invention.

FIG. 20 is a transverse sectional view illustrating a fingerprintreading device according to a sixth example embodiment of the presentinvention.

FIG. 21 is a longitudinal sectional view illustrating a fingerprintreading device according to a seventh example embodiment of the presentinvention.

FIG. 22 is a flowchart illustrating the operation of a fingerprintreading device and an image processing apparatus according to an eighthexample embodiment of the present invention.

FIG. 23 is a block diagram illustrating a function configuration of afingerprint reading device according to another example embodiment ofthe present invention.

DESCRIPTION OF EMBODIMENTS First Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto a first example embodiment of the present invention will be describedby using FIG. 1 to FIG. 10C.

First, the general configuration of the fingerprint reading systemincluding the fingerprint reading device according to the presentexample embodiment will be described by using FIG. 1 . FIG. 1 is aschematic diagram illustrating the general configuration of thefingerprint reading system according to the present example embodiment.

As illustrated in FIG. 1 , a fingerprint reading system 1 according tothe present example embodiment has a fingerprint reading device 10 thatcaptures and reads a fingerprint of a subject and an image processingapparatus 20 that performs processes such as display, recording, or thelike on a fingerprint image that is an image of a fingerprint read bythe fingerprint reading device 10. The fingerprint reading device 10 hasa placement portion 102 on which a finger of a subject is placed and aholding portion 104 that is held by a user when used. A sensor face 118with which a finger placed on the placement portion 102 comes intocontact is provided on the placement portion 102. The fingerprintreading device 10 is communicatively connected to the image processingapparatus 20 via the communication cable 30. Note that the fingerprintreading device 10 may be communicatively connected to the imageprocessing apparatus 20 by using a wireless scheme instead of a wiredscheme through the communication cable 30.

The fingerprint reading device 10 according to the present exampleembodiment is targeted for a newborn, an infant, and a young child as asubject whose fingerprint is read, for example. A finger of a newborn,an infant, and a young child, in particular, a finger of a newborn has ahigher moisture percentage and thus is softer than a finger of an adult,and a finger of a newborn may be more easily subjected to significantelastic deformation than a finger of an adult. The fingerprint readingdevice 10 according to the present example embodiment can appropriatelyread a fingerprint even in a case of a finger, such as a finger of anewborn, an infant, and a young child, which is relatively soft due to ahigh moisture percentage and may be easily subjected to significantelastic deformation, as described later. Note that it is impossible ordifficult for a newborn, an infant, a young child, or the like tocapture the fingerprint by himself/herself alone. When a fingerprint ofsuch a subject who is unable to capture or has difficulty in capturingan image of the fingerprint by himself/herself alone is to be read, anadult or the like who is able to operate a device will be a user, andthe user will have a fingerprint of a subject read, as described later.

The fingerprint reading device 10 is an optical fingerprint scanner thatcaptures a fingerprint image by using a two-dimensional image sensor andreads a fingerprint. The fingerprint reading device 10 can capture afingerprint image of any one of respective thumbs, index fingers, middlefingers, ring fingers, and little fingers of the left hand and the righthand of a subject, namely, the ten fingers in total, for example.Further, the fingerprint reading device 10 can capture a fingerprintimage of not only a finger of the hands but also any one of respectivefirst toes, second toes, third toes, fourth toes, and fifth toes of theleft foot and the right foot, namely, the ten fingers of feet (toes) intotal.

When a newborn, an infant, or a young child is a subject, for example,the fingerprint reading device 10 can be used to capture fingerprints ofa plurality of fingers or toes of a single subject and provide thesefingerprint images of the plurality of fingers or toes for recognitionof an individual. In this case, for example, for a single subject,fingerprints of the thumb of the left hand, the thumb of the right hand,the first toe of the left foot, and the first toe of the right foot canbe sequentially captured.

A specific configuration of the fingerprint reading device 10 accordingto the present example embodiment will be further described below byusing FIG. 2 to FIG. 7 . FIG. 2 is a plan view illustrating thefingerprint reading device 10 according to the present exampleembodiment, which illustrates a plane viewed from a top face side out ofthe front face and the back face of the fingerprint reading device 10.FIG. 3 is a longitudinal sectional view illustrating the fingerprintreading device 10 according to the present example embodiment, whichillustrates a vertical cross section taken along a line A-A of FIG. 2 .FIG. 4 is a horizontal cross section illustrating the fingerprintreading device 10 according to the present example embodiment, whichillustrates a horizontal cross section taken along a line B-B of FIG. 2. FIG. 5A and FIG. 5B are schematic diagrams illustrating an example ofa sensor drive unit in the fingerprint reading device 10 according tothe present example embodiment. FIG. 6 is a schematic diagramillustrating a view in which a fingerprint of a finger of a subject isread by using the fingerprint reading device 10 according to the presentexample embodiment. FIG. 7 is a block diagram illustrating thefingerprint reading device 10 according to the present exampleembodiment. Note that, in the first example embodiment and subsequentexample embodiments, the scale of each member is not the same in eachreferenced drawing, and each member may be depicted with exaggerationfor the purpose of illustration.

As illustrated in FIG. 2 to FIG. 4 , the fingerprint reading device 10according to the present example embodiment has a casing 106, an imagesensor 108, a sensor cover 110, a pair of side light sources 112, asensor drive unit 114, and a control circuit 116.

A casing 106 is a hollow member having an external shape of a verticallyflat, thin, approximate rectangular parallelepiped, and the longitudinaldirection thereof is a front-rear direction. The casing 106 is made of aresin, for example. Of the front-side part and the rear-side part alongthe longitudinal direction of the casing 106, the front-side part is theplacement portion 102, and the rear-side part is the holding portion104. The front end part of the placement portion 102 has a tapered shapeinclined from the backside face side to the top face side. Note that theexternal shape of the casing 106 is not limited to the external shape ofa flat, approximate rectangular parallelepiped, but any shape may beemployed.

The image sensor 108 is provided inside the casing 106 of the placementportion 102. The image sensor 108 is arranged such that the imagecapturing surface thereof faces the outside of the casing 106. A sensorcover 110 is provided on the image capturing surface of the image sensor108.

The surface of the sensor cover 110 forms the sensor face 118 that is areading face on which a ball of a finger of a subject whose fingerprintis to be read is placed and with which the placed ball of the fingercomes into contact. The sensor cover 110 is formed of a plate-likemember made of a material that transmits a near-infrared light, forexample, formed of a protection glass. Thereby, as described later, anear-infrared light is emitted from the pair of side light sources 112and enters the finger on the sensor cover 110, and the near-infraredlight emitted from the ball side of the finger enters the image sensor108 after scattering inside the finger.

The image capturing face of the image sensor 108 has a rectangularplanar shape having a larger area than the ball of a finger (toe) whosefingerprint is to be captured. At a capturing position described later,the image sensor 108 is arranged such that the longitudinal direction ofthe rectangular planar shape is in parallel to the front-rear directionof the casing 106. Note that the planar shape of the image sensor 108 isnot particularly limited, but various shapes may be employed. Further, aheatsink made of a metal or the like used for cooling the image sensor108 may be provided on the backside face of the image sensor 108.

The image sensor 108 functions as a reading unit that reads afingerprint of a finger. The image sensor 108 is configured to captureand read a fingerprint of a finger by receiving, on the image capturingface, a near-infrared light that has been emitted from the ball of thefinger in contact with the sensor face 118 of the sensor cover 110 andhas transmitted through the sensor cover 110, as described later. Theimage sensor 108 is a two-dimensional image sensor, for example, a CMOSimage sensor. Further, as the image sensor 108, a Charge Coupled Device(CCD) image sensor may be used other than the CMOS image sensor. Whilethe pixel density and the number of pixels of the image sensor 108 arenot particularly limited, for example, a high density such as 1000 ppior higher and a large number of pixels are preferable in taking intoconsideration of a case of capturing a fingerprint of a newborn, aninfant, a young child, or the like. Specifically, for example, a CMOSimage sensor having a large size of a width of 20 mm and a length of 30mm, a high pixel density of 1270 ppi, and a large number of pixels canbe used as the image sensor 108.

The front end part of the image sensor 108 is attached to a top plate atthe front end of the placement portion 102 in the casing 106 via a hingepart 120. The hinge part 120 includes a rocking shaft extending in thewidth direction of the placement portion 102 in the casing 106. Notethat the front side or the front end part of the image sensor 108 refersto the end part of the fingerprint reading device 10, that is, the endpart, which is located opposite to the holding portion 104, of theplacement portion 102. Further, the rear side or the rear end part ofthe image sensor 108 refers to the center part of the fingerprintreading device 10, that is, the end part, which is located on theholding portion 104 side, of the placement portion 102.

The image sensor 108 and the sensor cover 110 including the sensor face118 are provided so as to be able to swing about a rocking shaft of thehinge part 120 located at the front side end of the placement portion102 as a fulcrum. This enables the image sensor 108 and the sensor cover110 including the sensor face 118 to move between a capturing position,which is a first position, and a recessed position, which is a secondposition located inside the casing 106 deeper than the capturingposition.

At the capturing position, the image sensor 108 and the sensor cover 110are arranged such that the sensor face 118 of the sensor cover 110 isorthogonal to the perpendicular direction of the placement portion 102.Further, the image sensor 108 and the sensor cover 110 positioned at thecapturing position seal the inside of the placement portion 102. On theother hand, at the recessed position, the image sensor 108 and thesensor cover 110 are arranged such that the sensor face 118 of thesensor cover 110 is inclined to face the rearward oblique upperdirection relative to the placement portion 102.

The image sensor 108 and the sensor cover 110 including the sensor face118 are driven by the sensor drive unit 114 and move between thecapturing position and the recessed position. At the capturing position,the sensor face 118 contacts with the ball of the finger placed on theplacement portion 102. In contrast, at the recessed position, the sensorface 118 separates from the ball of the finger placed on the placementportion 102.

In FIG. 3 , the image sensor 108 and the sensor cover 110 at thecapturing position are illustrated by the solid line, and the imagesensor 108 and the sensor cover 110 at the recessed position areillustrated by the one-dot-chain line. As illustrated, the sensor face118 of the sensor cover 110 at the capturing position is orthogonal tothe perpendicular direction of the placement portion 102 and forms aflat face with the surface of the holding portion 104 with substantiallyno step. On the other hand, the sensor face 118 of the sensor cover 110at the recessed position is inclined so as to enter the inside of thecasing 106 in the direction from the front side to the rear side of theplacement portion 102.

The pair of side light sources 112 are provided above regions on bothsides of the sensor face 118 in the placement portion 102 of the casing106. Each of the pair of the side light sources 112 forms a line lightsource provided so as to extend in the front-rear direction of theplacement portion 102 that is the longitudinal direction of the casing106. The pair of side light sources 112 are provided on both endportions of the sensor face 118, which are opposed to each other in thewidth direction of the placement portion 102, and face each other in thewidth direction of the placement portion 102 via the sensor face 118.Each of the pair of side light sources 112 is a light source thatirradiates a finger placed on the sensor face 118 of the placementportion 102 with near-infrared light.

Each side light source 112 has a plurality of near-infrared LEDs 122 andlight guiding parts 124 formed to cover the plurality of near-infraredLEDs 122. In each side light source 112, the plurality of near-infraredLEDs 122 are arranged so as to be aligned in a line in the front-reardirection of the placement portion 102. The plurality of near-infraredLEDs 122 arranged in each line are covered with the light guiding part124 provided in the front-rear direction of the placement portion 102.

Each of the plurality of near-infrared LEDs 122 forms a unit lightsource forming a line light source, respectively, and emitsnear-infrared light of a wavelength of 820 to 980 nm, for example. Eachnear-infrared LED 122 is provided at the same height as the sensor face118 in the capturing position or a height higher than the sensor face118 at the capturing position in the perpendicular direction of thecasing 106. Further, each near-infrared LED 122 is arranged inclinedsuch that the light axis thereof is oriented to the center upper spaceof the sensor face 118 at the capturing position. Each near-infrared LED122 is arranged inclined such that the angle of the light axis relativeto the sensor face 118 is greater than 0 degree and less than 90degrees, for example.

With each near-infrared LED 122 being arranged inclined in such a way,each of the side light sources 112, which is a line light source, isconfigured such that the light axis thereof is inclined inward above thesensor face 118 positioned at the capturing position and oriented to thecenter upper space of the sensor face 118. Each side light source 112 isarranged such that the angle of the light axis relative to the sensorface 118 is greater than 0 degree and less than 90 degrees, for example.With the light axis of each side light source 112 being inclined inwardabove the sensor face 118 as discussed above, each of the side lightsources 112 is able to irradiate a finger placed on the sensor face 118of the placement portion 102 with a sufficient light amount ofnear-infrared light.

The light guiding part 124 is formed of a light-transmitting resin suchas a silicone, for example, or other light-transmitting materials. Notethat the light-transmitting material forming the light guiding part 124is not particularly limited as long as it has a transmittance to thenear-infrared light emitted from the plurality of near-infrared LEDs122, and various light-transmitting materials may be used.

The light guiding parts 124 are formed in the front-rear direction ofthe placement portion 102 so as to cover the plurality of near-infraredLEDs 122 that form a plurality of unit light sources each aligned in aline in the front-rear direction of the placement portion 102. The lightguiding part 124 covering the plurality of near-infrared LEDs 122scatters and guides near-infrared lights emitted from the plurality ofnear-infrared LEDs 122 and emits the near-infrared lights to a fingerplaced on the sensor face 118 of the placement portion 102.

Each of the light guiding parts 124 has a ridge-like protrusion part 126and a skirt-like edge part 128 formed integrally with the protrusionpart 126. The protrusion part 126 is formed in a ridge-like manner so asto cover the plurality of near-infrared LEDs 122 and protrude above theplacement portion 102. The edge part 128 is formed in a skirt-likemanner integrally with the protrusion part 126 so as to extend on thesensor face 118 side of the protrusion part 126 continuously from theprotrusion part 126 on the sensor face 118 side. The edge part 128 has alower height in the perpendicular direction of the placement portion 102than the protrusion part 126, and the height thereof gradually decreasestoward the sensor face 118 side.

The protrusion part 126 has a convex surface protruding to the upwardside of the placement portion 102 that is the opposite side of thesensor face 118, for example. On the other hand, the edge part 128 has aconvex surface protruding to the downward side of the placement portion102 that is the sensor face 118 side, for example.

Each of the light guiding parts 124 is formed so as to partiallyprotrude and extend up to above the end of the sensor face 118. Morespecifically, in the light guiding part 124, the edge part 128 and apart of the protrusion part 126 on the edge part 128 side protrude overthe end of the sensor face 118 and are located on the end of the sensorface 118. The partially protruding light guiding part 124 as discussedabove is configured such that the surface thereof on the sensor face 118side comes into contact with the surface of a finger on the sensor face118 side placed on the sensor face 118. As discussed above, by beingformed so as to partially protrude and extend up to above the end of thesensor face 118, the light guiding part 124 is configured to be able tosupport a finger placed on the placement portion 102.

The protrusion width, which is a width formed of the edge part 128 and apart of the protrusion part 126 on the edge part 128 side protruding andlocated over the end of the sensor face 118, is constant over thefront-rear direction of the placement portion 102. The protrusion widthof the edge part 128 and a part of the protrusion part 126 on the edgepart 128 side is not particularly limited and can be appropriately setin accordance with the size of a finger of the age group of a subject orthe like. For example, when a newborn is a subject, each of the lightguiding parts 124 on both sides may be configured such that theprotrusion width of the edge part 128 and a part of the protrusion part126 on the edge part 128 side is 5 mm, respectively, with respect to theimage sensor 108 of a width of 20 mm. In this case, the width of thesensor face 118 exposed between both the edge parts 128 is 10 mm.

Light shielding parts 130 are each provided on the under surface, whichis on the sensor face 118 side, of the edge part 128 and a part of theprotrusion part 126, which is a part located protruding over the end ofthe sensor face 118 of the light guiding part 124. The under surface ofthe sensor face 118 side of the edge part 128 and a part of theprotrusion part 126 provided with the light shielding part 130 is a flatsurface parallel to the sensor face 118 at the capturing position.

The light shielding part 130 is provided for preventing thenear-infrared light emitted from the near-infrared LEDs 122 fromdirectly entering the image sensor 108 from the protrusion part 126 andthe edge part 128 without passing through a finger. By using the lightshielding part 130 to prevent the near-infrared light from directlyentering the image sensor 108 without passing through a finger, it ispossible to reduce a noise light and acquire a higher qualityfingerprint image. Note that the light shielding part 130 may be of areflection type that blocks near-infrared light by reflectingnear-infrared light entering the light shielding part 130 or may be ofan absorption type that blocks near-infrared light by absorbingnear-infrared light entering the light shielding part 130. As the lightshielding part 130, a film, a foil, a sheet, or other light shieldingmember made of a light shielding material that blocks near-infraredlight by reflecting or absorbing the near-infrared light as discussedabove can be used.

In the fingerprint reading device 10 according to the present exampleembodiment, in the light guiding part 124, a finger on the sensor face118 can be irradiated with near-infrared lights not only from theprotrusion part 126 but also from the edge part 128 that is closer tothe sensor face 118 than the protrusion part 126. Furthermore, the edgepart 128 or the edge part 128 and the protrusion part 126 is in contactwith the surface, which is on the sensor face 118 side, of a fingerplaced on the sensor face 118. The use of the edge part 128 describedabove can increase the light amount of near-infrared light entering thefinger on the sensor face 118. Therefore, according to the presentexample embodiment, a high quality fingerprint image with a highcontrast can be acquired.

Further, the light guiding part 124 in each side light source 112 notonly guides the near-infrared lights emitted from the plurality ofnear-infrared LEDs 122 as described above but also functions as asupport part configured to be able to support a finger placed on thesensor face 118 of the placement portion 102. That is, in the lightguiding part 124, the edge part 128 and a part of the protrusion part126 located protruding over the end of the sensor face 118 contact withthe surface of a finger F on the sensor face 118 side placed on thesensor face 118 and support the finger F from the sensor face 118 side,as illustrated in FIG. 4 . With such the light guiding part 124 beingprovided, it is possible to stably support a finger whose fingerprint isto be captured and suppress or even prevent displacement of the fingerfrom the sensor face 118.

In particular, the fingerprint reading device 10 according to thepresent example embodiment is configured such that the image sensor 108and the sensor cover 110 including the sensor face 118 move between thecapturing position and the recessed position as described above. In sucha configuration, the edge part 128 and a part of the protrusion part 126contact with the surface of the finger F on the sensor face 118 side andsupport the finger F from the sensor face 118 side. This can suppress oreven prevent displacement of the finger F due to motion of the imagesensor 108 and the sensor cover 110. For example, even when the imagesensor 108 and the sensor cover 110 move from the capturing position tothe recessed position, displacement of the finger F due to the motioncan be suppressed or even prevented.

The image sensor 108 captures and reads a fingerprint of a finger placedon the sensor face 118 at the capturing position. Here, the sensor driveunit 114 causes the sensor face 118 in contact with the finger at thecapturing position to move from the capturing position to the recessedposition and further move and return from the recessed position to thecapturing position, as described later. In this case, the image sensor108 captures and reads a fingerprint of the finger in contact with thesensor face 118 that has returned from the recessed position to thecapturing position.

The image sensor 108 captures and reads a fingerprint by using anear-infrared light scattered inside a finger and emitted from thesurface of the finger. The principle by which a fingerprint is capturedby the image sensor 108 will be described below. When a fingerprint iscaptured, near-infrared lights are emitted from the pair of side lightsources 112 with the ball of a finger being in contact with the sensorface 118 of the sensor cover 110. The near-infrared lights emitted fromthe pair of side light sources 112 that enter the finger on the sensorcover 110. The near-infrared lights that have entered the finger arescattered inside the finger and emitted outside the finger from thesurface of the finger. The near-infrared lights emitted outside thefinger have different intensities in accordance with whether emittedfrom the ridge part of the fingerprint or emitted from the valley partof the fingerprint.

Since the ridge part is in contact with the sensor face 118 of thesensor cover 110, the near-infrared light emitted outside the fingerfrom the ridge part of the fingerprint reaches and enters the imagesensor 108 with a relatively high intensity without significantattenuation. In contrast, since the valley part is not in contact withthe sensor face 118, the near-infrared light emitted outside the fingerfrom the valley part of the fingerprint is scattered by the air layerpresent between the valley part and the sensor face 118. In addition,reflection and refraction occurs due to a refractive index difference atthe interface between the skin and the air and between the air and thesensor cover 110. Thus, the near-infrared light emitted from the valleypart significantly attenuates compared to the near-infrared lightemitted from the ridge part and reaches and enters the image sensor 108with a relatively low intensity or is unable to reach the image sensor108.

As a result, a fingerprint image in which a brightness difference ispresent between the ridge part and the valley part of the fingerprint iscaptured on the image sensor 108. That is, in the captured fingerprintimage, the ridge part of the fingerprint corresponds to a bright part,and the valley part of the fingerprint corresponds to a dark part. Thenear-infrared lights scattered inside a finger and emitted outside thefinger are received by the image sensor 108 in such a way, and thereby afingerprint is captured.

The image sensor 108 that has captured a fingerprint of a finger outputsimage data forming the fingerprint image. As described later, the imagedata output from the image sensor 108 is processed in the controlcircuit 116 and transferred to the image processing apparatus 20 via thecommunication cable 30. The image processing apparatus 20 to which theimage data is transferred performs display, recording, or the like ofthe fingerprint image based on the transferred image data.

The sensor drive unit 114 is provided under the rear end part of theimage sensor 108 inside the casing 106 of the placement portion 102. Thesensor drive unit 114 is a drive unit that drives the rear end part ofthe image sensor 108, which is attached to the casing 106 so as to beable to swing, to move up and down and causes the image sensor 108 andthe sensor cover 110 including the sensor face 118 to swing and move.

Specifically, the sensor drive unit 114 causes the rear end part of theimage sensor 108 positioned at the capturing position to move down andcauses the image sensor 108 and the sensor cover 110 including thesensor face 118 to swing and move from the capturing position to therecessed position. Further, the sensor drive unit 114 causes the rearend part of the image sensor 108 positioned at the recessed position tomove up and causes the image sensor 108 and the sensor cover 110including the sensor face 118 to swing and move from the recessedposition to the capturing position. In such a way, the sensor drive unit114 causes the image sensor 108 and the sensor cover 110 including thesensor face 118 to move from the capturing position to the recessedposition and further move and return from the recessed position to thecapturing position.

The configuration of the sensor drive unit 114 is not limited to aparticular configuration but may be any configuration that can move upand down the rear end part of the image sensor 108. For example, thesensor drive unit 114 may have a solenoid-type configuration in which asolenoid is used as an actuator. FIG. 5A and FIG. 5B illustrate anexample having solenoid-type configuration as an example of the sensordrive unit 114. FIG. 5A is a side view illustrating a solenoid-typesensor drive unit 114 when the image sensor 108 is positioned at thecapturing position. FIG. 5B is a side view illustrating a solenoid-typesensor drive unit 114 when the image sensor 108 is positioned at therecessed position.

As illustrated in FIG. 5A and FIG. 5B, the solenoid-type sensor driveunit 114 has a solenoid 132, a contact part 134, and an elastic member136.

The solenoid 132 has a plunger 138 and a base part 140 including a coil,which is a pull-type solenoid in which the plunger 138 is pulled intothe base part 140 in a conduction state. The base part 140 of thesolenoid 132 is provided on the bottom of the casing 106 so that theplunger 138 operates in the perpendicular direction of the casing 106.

The contact part 134 is attached to the upper end of the plunger 138.The contact part 134 comes into contact with the underside of the rearend part of the image sensor 108 and supports the rear end part of theimage sensor 108. The elastic member 136 such as a spring that actuatesthe contact part 134 to the image sensor 108 side is provided betweenthe contact part 134 and the base part 140.

In a non-conduction state of the solenoid 132, as illustrated in FIG.5A, the plunger 138 is not pulled into the base part 140. Furthermore,the contact part 134 is actuated to the image sensor 108 side by theelastic member 136. The contact part 134 actuated by the elastic member136 comes into contact with the underside of the rear end part of theimage sensor 108 and supports the rear end part of the image sensor 108.In the non-conduction state, the image sensor 108 and the sensor cover110 including the sensor face 118 are positioned at the capturingposition.

On the other hand, when a current is applied to the solenoid 132, theplunger 138 is pulled into the base part 140. When the plunger 138 ispulled into the base part 140, the contact part 134 moves down againstthe actuation force applied by the elastic member 136. In response, therear end part of the image sensor 108 supported by the contact part 134also moves down. Thus, the contact part 134 comes into contact with theunderside of the rear end part of the image sensor 108 at a positionlower than the position in the non-conduction state and supports theimage sensor 108, as illustrated in FIG. 5B. In such a way, in theconduction state, the image sensor 108 and the sensor cover 110including the sensor face 118 are positioned at the recessed position.

Furthermore, when the current applied to the solenoid 132 is stopped,pulling of the plunger 138 into the base part 140 is released.Furthermore, the plunger 138 and the contact part 134 move up due to theactuation force of the elastic member 136 to return to the initialposition that is a non-conduction state. In response, the rear end partof the image sensor 108 supported by the contact part 134 also moves up.In such a way, in a non-conduction state after a conduction state, theimage sensor 108 and the sensor cover 110 including the sensor face 118return to the capturing position.

As discussed above, the solenoid-type sensor drive unit 114 moves downand up the rear end part of the image sensor 108 by using the contactpart 134 attached to the plunger 138. Thereby, the sensor drive unit 114causes the image sensor 108 and the sensor cover 110 including thesensor face 118 to swing and causes the image sensor 108 and the sensorcover 110 including the sensor face 118 to move between the capturingposition and recessed position.

As described above, the solenoid-type one using the solenoid 132 can beused as the sensor drive unit 114. Note that the drive mechanism of thesensor drive unit 114 that moves the image sensor 108 and the sensorcover 110 is not limited to the electric mechanism using the solenoid132 described above. The drive mechanism of the sensor drive unit 114may be other electric mechanisms using a drive motor, a linear actuator,or the like that is driven electrically or may be a mechanical mechanismusing a handle, a lever, a link, an arm, or the like that can beoperated manually.

The holding portion 104 that is a rear side portion of the casing 106 isa portion held by the user who captures a finger of a subject whosefingerprint is to be captured when the fingerprint is captured.

A newborn, an infant, a young child, or the like is one who is unable tocapture or has difficulty in capturing a fingerprint by himself/herselfalone. Thus, a user who is an adult or a minor who is able to operatethe device by himself/herself alone operates the fingerprint readingdevice 10 to capture a fingerprint of a finger of a subject who is anewborn, an infant, a young child, or the like. The user holds theholding portion 104 by one hand and moves the fingerprint reading device10 from the front side thereof, namely, from the placement portion 102toward the finger such as the thumb of the subject whose fingerprint isto be captured. The user is able to hold the holding portion 104 fromthe side such that, among the fingers of the hand holding the holdingportion 104, the thumb is positioned on the top plate side of the casing106 and the four fingers other than the thumb are positioned on thebottom plate side of the casing 106, for example. Furthermore, asillustrated in FIG. 6 , the user is able to cause the ball of the fingerof the subject to come into contact with the sensor face 118 of thesensor cover 110 while using the other hand if necessary. Note that,although not illustrated in FIG. 6 , the user is able to use thefingertip of the thumb or the like of his/her hand which holds theholding portion 104 to press the finger of the subject that is incontact with the sensor face 118 and fix the position thereof.

A push button-type motion switch 142 is provided on the bottom face ofthe holding portion 104 held by the user. The motion switch 142 isconfigured to, when pressed, be able to drive the sensor drive unit 114and move the image sensor 108 and the sensor cover 110 including thesensor face 118. That is, the motion switch 142 is configured to, whenpressed, be able to cause the image sensor 108 and the sensor cover 110to move from the capturing position to the recessed position and furthermove and return from the recessed position to the capturing position.

Further, a push button-type capture switch 144 is provided on the bottomface of the holding portion 104. The capture switch 144 is configuredto, when pressed, be able to instruct the side light sources 112 to beturned on or off, instruct the image sensor 108 to capture afingerprint, or instruct the image processing apparatus 20 to record afingerprint image.

The user holding the holding portion 104 is able to press the motionswitch 142 and the capture switch 144 by any of four fingers positionedon the bottom plate side of the casing 106 out of the fingers of a handholding the holding portion 104 while holding the holding portion 104.

Further, the motion switch 142 is formed so as to be embedded in theholding portion 104 such that the pressing face of the motion switch 142and the bottom face of the holding portion 104 are substantially flatwith each other. Also, the capture switch 144 is formed so as to beembedded in the holding portion 104 such that the pressing face of thecapture switch 144 and the bottom face of the holding portion 104 aresubstantially flat with each other. With the motion switch 142 and thecapture switch 144 being provided so as not to protrude from the bottomface of the holding portion 104 in such a way, erroneous press of themotion switch 142 and the capture switch 144 can be suppressed.

The control circuit 116 is accommodated inside the holding portion 104of the casing 106. Further, a connector unit 146 to which thecommunication cable 30 is connected is provided on the side end part onthe rear side of the holding portion 104.

FIG. 7 is a block diagram illustrating respective components of thefingerprint reading device 10 described above, which illustrates theimage sensor 108, the side light source 112, the sensor drive unit 114,and the control circuit 116 in detail.

As illustrated in FIG. 7 , the image sensor 108 has a pixel array 148and a timing generator 150. Further, the image sensor 108 has a verticalscanning circuit 152, a column amplifier circuit 154, ananalog-to-digital (A/D) converter circuit 156, a horizontal scanningcircuit 158, and a signal processing circuit 160.

A plurality of pixels are provided in a matrix in the pixel array 148.Each pixel has a photoelectric conversion element that generates a pixelsignal by photoelectrically converting an incident near-infrared light.The timing generator 150 generates and outputs a timing signal used forcontrolling the vertical scanning circuit 152 and the horizontalscanning circuit 158. The vertical scanning circuit 152 scans the pixelsof the pixel array 148 on a pixel row basis. The column amplifiercircuit 154 amplifies pixel signals read by scans performed by thevertical scanning circuit 152. The A/D converter circuit 156 convertspixel signals amplified by the column amplifier circuit 154 from analogsignals to digital signals. The horizontal scanning circuit 158 performsscans on a pixel column basis to read pixel signals converted by the A/Dconverter circuit 156 to the outside. The signal processing circuit 160performs predetermined signal processing on the pixel signal read by thehorizontal scanning circuit 158 and output from the A/D convertercircuit 156 to output image data forming a fingerprint image. The imagedata output from the signal processing circuit 160 is input to thecontrol circuit 116.

In the side light source 112, a current limiting resistor 162 thatrestricts a current flowing in the near-infrared LED 122 and atransistor 164 that serves as a switch are connected to each of theplurality of near-infrared LED 122.

One of the terminals of the current limiting resistor 162 is connectedto the anode side terminal of each near-infrared LED 122. The collectorof each transistor 164 is connected to the cathode side terminal of eachnear-infrared LED 122. A positive power source voltage VDD is input tothe other terminal of each current limiting resistor 162. The base ofeach transistor 164 is connected to the control circuit 116, and thetransistor 164 is switched to be turned on and off by a switch signalinput to the base from the control circuit 116.

The control circuit 116 has a central processing unit (CPU) 166, a readonly memory (ROM) 168, and a random access memory (RAM) 170. Further,the control circuit 116 has a video controller 172, an interface (I/F)174, and a communication controller 176. Furthermore, the controlcircuit 116 has a voltage regulator 178. The CPU 166, the ROM 168, theRAM 170, the video controller 172, the I/F 174, and the communicationcontroller 176 are connected to a common bus line 180.

The CPU 166 executes a program for controlling the operation of thefingerprint reading device 10 to control the operation of each unit ofthe fingerprint reading device 10. The ROM 168 stores a program executedby the CPU 166. Further, the RAM 170 is a working area when the CPU 166executes a program.

The video controller 172 is connected to the signal processing circuit160 of the image sensor 108, and image data is input from the signalprocessing circuit 160. The video controller 172 transfers image data tothe communication controller 176 via the bus line 180.

The timing generator 150 of the image sensor 108 is connected to the I/F174. Thereby, the control signal by the CPU 166 is input to the timinggenerator 150 via the I/F 174. The timing generator 150 generates andoutputs a timing signal based on a control signal input via the I/F 174.

Further, the bases of the plurality of transistors 164 in the side lightsource 112 are connected to the I/F 174. Thereby, the switch signal fromthe CPU 166 is input to the base of the transistors 164 via the I/F 174.The transistor 164 is switched to be turned on and off based on a switchsignal input via the I/F 174. In response to the transistor 164 beingswitched to be turned on and off, the near-infrared LED 122 is switchedto be turned on and off, and thereby the side light source 112 isswitched to be turned on and off.

The sensor drive unit 114 has the solenoid 132 and a driver 182 thatcontrols driving of the solenoid 132. The driver 182 is connected to theI/F 174. Thereby, a control signal from the CPU 166 is input to thedriver 182 via the I/F 174. The driver 182 controls driving of thesolenoid 132 based on the control signal input via the I/F 174.

The motion switch 142 is connected to the I/F 174. The output of acontrol signal of the driver 182 from the CPU 166 is triggered inresponse to press of the motion switch 142.

Specifically, in a state before a fingerprint is read by the imagesensor 108, the image sensor 108 and the sensor cover 110 including thesensor face 118 are positioned at the capturing position. When themotion switch 142 is pressed, the solenoid 132 is driven by the driver182 in the sensor drive unit 114. Thereby, the image sensor 108 and thesensor cover 110 including the sensor face 118 move from the capturingposition to the recessed position and further move and return from therecessed position to the capturing position.

Note that the motion switch 142 is not necessarily required to beprovided. Instead, such a configuration is possible in which, inresponse to detection of contact of a finger with the sensor face 118,output of the control signal of the driver 182 is triggered, and theimage sensor 108 and the sensor cover 110 including the sensor face 118are moved from the capturing position toward the recessed position bythe sensor drive unit 114, in the same manner as described above. Insuch a configuration without the motion switch 142 being provided,contact of the finger on the sensor face 118 can be detected based on achange in an image captured by the image sensor 108, for example, or canbe detected by a sensor that can detect contact thereon, such as a touchsensor provided on the sensor face 118.

Further, the operating time period in which the image sensor 108 and thesensor cover 110 return to the capturing position via the recessedposition from the capturing position is not particularly limited but maybe set as appropriate. However, it is preferable to set this operatingtime period to a time period during which elastic deformation of afinger that once comes into contact with the sensor face 118 issufficiently reduced.

Further, the capture switch 144 is connected to the I/F 174. In responseto the capture switch 144 being pressed, output of a control signal ofthe image sensor 108 and a switch signal of the side light source 112from the CPU 166 are triggered.

Specifically, in a non-operating state of the image sensor 108, the sidelight source 112 is also in a turn-off state, and when the captureswitch 144 is pressed under this state, the side light source 112 isturned off and the image sensor 108 starts capturing a fingerprint. Theimage sensor 108 that has captured a fingerprint outputs image data ofthe captured fingerprint image. After outputting the image data, theimage sensor 108 is in a non-operating state, and the side light source112 is in a turn-off state. The image data of the fingerprint imageoutput by the image sensor 108 is transferred to the image processingapparatus 20.

The communication controller 176 functions as a transfer unit thattransfers image data of the fingerprint image, which transfers imagedata transferred from the video controller 172 to the image processingapparatus 20 via the communication cable 30 connected to the connectorunit 146. The communication controller 176 is configured to communicatewith the image processing apparatus 20 via the communication cable 30 inaccordance with a communication standard such as Universal Serial Bus(USB) or the like, for example.

The communication cable 30 is configured to have two differential signallines for transmitting and receiving signals, a power source line forpower supply, and a ground line. The communication controller 176transmits and receives signals through the two differential signal linesin the communication cable 30.

The power source line of the communication cable 30 is connected to thevoltage regulator 178, and power is supplied via the power source linefrom a power source circuit 216 (see FIG. 8 ) in the image processingapparatus 20. The voltage regulator 178 adjusts the voltage of thesupplied power and supplies it as a power source to each unit of thefingerprint reading device 10. The fingerprint reading device 10 is of abus-power system so as to operate by power supplied via thecommunication cable 30 from the image processing apparatus 20 in such away. Note that the fingerprint reading device 10 may be operated bypower supplied from a built-in battery, for example, without limited tothe bus-power system.

On the other hand, the image processing apparatus 20 functions as animage processing unit that performs processes such as display,recording, or the like on a fingerprint image transferred from thefingerprint reading device 10 that has captured a fingerprint. The imageprocessing apparatus 20 may be formed of a personal computer (PC) deviceof a laptop type, a tablet type, or the like, for example. Further,image processing apparatus 20 can control the operation of thefingerprint reading device 10. Note that the image processing apparatus20 is not necessarily required to include the display 214 describedlater, and the image processing unit can be configured as including nodisplay unit.

The specific configuration of the image processing apparatus 20 will befurther described below by using FIG. 8 . FIG. 8 is a block diagramillustrating the image processing apparatus 20.

As illustrated in FIG. 8 , the image processing apparatus 20 has a CPU202, a ROM 204, a RAM 206, a hard disk drive (HDD) 208, and acommunication controller 210. Further, the image processing apparatus 20has a display controller 212 and the display 214. Further, the imageprocessing apparatus 20 has the power source circuit 216 and an inputdevice 218. The CPU 202, the ROM 204, the RAM 206, the HDD 208, thecommunication controller 210, display controller 212, the power sourcecircuit 216, and the input device 218 are connected to a common bus line220. Further, a connector unit 222 to which the communication cable 30is connected is provided to the image processing apparatus 20.

The CPU 202 controls the entire operation of the image processingapparatus 20. Further, the CPU 202 executes an image processing programused for display, recording, or the like of a fingerprint image acquiredby the fingerprint reading device 10. The image processing programperforms image processing on image data transferred from the fingerprintreading device 10 and performs display, recording, or the like of afingerprint image thereof.

The ROM 204 stores therein a program such as a boot program. The RAM 206is used as a working area when the CPU 202 executes a process. Further,the RAM 206 functions as an image memory in which image data of afingerprint image transferred from the fingerprint reading device 10 istemporarily stored. The HDD 208 stores a program such as an imageprocessing program executed by the CPU 202.

Further, the HDD 208 functions as a recording unit that records afingerprint image captured by the fingerprint reading device 10. The CPU202 functions as a record control unit to record a fingerprint image inthe HDD 208. Note that the recording unit that records a fingerprintimage is not limited to the HDD 208 and, instead of the HDD 208, variousrecording devices may be used as the recording unit. The recording unitthat records a fingerprint image may be built in the image processingapparatus 20 similarly to the HDD 208 or may be an independent externalrecording device separate from the image processing apparatus 20.

The communication controller 210 functions as a receiving unit thatreceives image data of a fingerprint image to receive image datatransferred from the communication controller 176 of the fingerprintreading device 10 via the communication cable 30 connected to theconnector unit 222. The image data received by the communicationcontroller 210 is temporarily stored in the RAM 206 as an image memory.The communication controller 210 is configured to communicate with thefingerprint reading device 10 via the communication cable 30 inaccordance with a communication standard such as USB or the like, forexample, in association with the communication controller 176. Thecommunication controller 210 is configured to transmit and receivesignals by two differential signal lines in the communication cable 30in association with the communication controller 176.

The display 214 that functions as a display unit that displays afingerprint image is connected to the display controller 212. Thedisplay controller 212 cooperates with the CPU 202 to function as adisplay control unit and renders and displays a display window of animage processing program executed by the CPU 202 on the display 214. Thedisplay window of the image processing program displayed on the display214 includes a preview window in which a captured fingerprint image isdisplayed. Note that, while not limited in particular, the display 214is a liquid crystal display, for example. Further, the display 214 maybe built in the image processing apparatus 20, which is a laptop PC, atablet PC, or the like, or may be an external display providedseparately from the image processing apparatus 20.

The power source circuit 216 supplies power of a built-in power sourceof the image processing apparatus 20 or power of an external powersource connected to the image processing apparatus 20 to the fingerprintreading device 10. The power source circuit 216 is connected to thepower source line and the ground line of the communication cable 30 andsupplies power to the voltage regulator 178 of the fingerprint readingdevice 10 via the power source line.

The input device 218 is a keyboard, a mouse, or the like, for example.Further, the input device 218 may be a touch panel embedded in thedisplay 214. An operator can input text information such as anidentification number (ID), a name, or the like of a subject or selectinformation regarding the type of a finger in the image processingprogram displayed on the display 214 via the input device 218. Further,setting of capturing conditions or the like may be performed.

The fingerprint reading system 1 according to the present exampleembodiment is configured as described above.

Next, the operation of the fingerprint reading device 10 according tothe present example embodiment will be further described by using FIG.9A to FIG. 9C and FIG. 10A to FIG. 10C. FIG. 9A to FIG. 9C are schematicdiagrams illustrating the operation of the fingerprint reading device 10according to the present example embodiment. FIG. 9A to FIG. 9Cillustrate the positional relationship of the finger F with the imagesensor 108 and the sensor cover 110 after the finger F comes intocontact with the sensor face 118 and before a fingerprint is captured.For simplified illustration, the side light sources 112 are omitted inFIG. 9A to FIG. 9C. FIG. 10A to FIG. 10C are schematic diagramsillustrating the principle by which elastic deformation of a fingerprintis reduced when the fingerprint is read by the fingerprint readingdevice 10 according to the present example embodiment. FIG. 10A is aschematic diagram schematically illustrating an ideal fingerprint to beread. FIG. 10B is a schematic diagram schematically illustrating afingerprint to be read from a finger which is subjected to significantelastic deformation. FIG. 10C is a schematic diagram schematicallyillustrating a fingerprint to be read from a finger in which elasticdeformation has been reduced.

In a state where the operation of the fingerprint reading device 10 isstopped, the image sensor 108 and the sensor cover 110 including thesensor face 118 are positioned at the capturing position. First, in astate where the image sensor 108 and the sensor cover 110 are positionedat the capturing position, the user causes the ball of the finger F ofthe subject to come into contact with the sensor face 118 of thefingerprint reading device 10, as illustrated in FIG. 9A. For example,the sensor face 118 is slid onto the ball of the finger F from the frontside of the placement portion 102, which is the front side of the casing106, so that the finger F is directed in the longitudinal direction ofthe casing 106, that is, the front-rear direction of the placementportion 102, and thereby the ball of the finger F comes into contactwith the sensor face 118.

In a state where the ball of the finger F is in contact with the sensorface 118, for each of the pair of side light sources 112, the edge part128 and a part of the protrusion part 126 located protruding over theend of the sensor face 118 come into contact with the surface of thefinger F on the sensor face 118 side placed on the sensor face 118. Theedge part 128 and a part of the protrusion part 126 in contact with thesurface on the sensor face 118 side of the finger F support the finger Fin contact with the sensor face 118 from the sensor face 118 side.

When the finger F comes into contact with the sensor face 118 asdescribed above, however, a large elastic deformation may occur in thefinger F in contact with the sensor face 118 due to force received in asliding direction of the sensor face 118 and other force. In particular,in a case of the finger F such as a finger of a newborn or an infant,because of a high moisture percentage, the finger F is relatively soft,and large elastic deformation may occur. Further, when the sensor face118 is slid onto the ball of the finger F as described above, a portionon the tip side of the finger F will receive force over longer time in asliding direction of the sensor face 118 than a portion on the baseside. Thus, more significant elastic deformation may occur in theportion on the tip side of the finger F than in the portion on the baseside.

When a fingerprint is read in a state where large elastic deformationoccurs in the finger F, the read fingerprint is significantly deformedentirely or locally and is fully different from the ideal fingerprint.For example, compared to the ideal fingerprint illustrated in FIG. 10A,a fingerprint read from the finger F where large elastic deformationoccurs shrinks entirely in the sliding direction of the sensor face 118,that is, the longitudinal direction of the finger F as illustrated inFIG. 10B. Note that a fingerprint may not only shrink but also deform invarious manners such as expanding, bending, or the like in response toforce applied to the finger F. Further, a fingerprint may be deformedentirely as illustrated in FIG. 10B, or a part thereof may be deformedlocally.

Next, in a state where the ball of the finger F is in contact with thesensor face 118, the user may press the motion switch 142. With themotion switch 142 being pressed, a drive instruction signal is input toinstruct the fingerprint reading device 10 to drive the image sensor 108and the sensor cover 110.

The CPU 166 of the fingerprint reading device 10 drives the sensor driveunit 114 in response to the drive instruction signal input by press ofthe motion switch 142 and drives the image sensor 108 and the sensorcover 110 including the sensor face 118. Thereby, the image sensor 108and the sensor cover 110 including the sensor face 118 swing about arocking shaft of the hinge part 120 attached to the casing 106 of thefront end part of the image sensor 108 as a fulcrum.

Note that, in a configuration without the motion switch 142 beingprovided, in response to detection of contact of the ball of the fingerF with the sensor face 118 instead of the motion switch 142 beingpressed, the drive instruction signal is input, and the image sensor 108and the sensor cover 110 including the sensor face 118 are driven by thesensor drive unit 114 in the same manner as described above.

The image sensor 108 and the sensor cover 110 including the sensor face118 that swing first move from the capturing position to the recessedposition with the rear end part thereof moving down, as illustrated inFIG. 9B. At the recessed position, the sensor face 118 separates fromthe ball of the finger F. In a configuration without the motion switch142 being provided, in response to detection of contact of the ball ofthe finger F with the sensor face 118, the image sensor 108 and thesensor cover 110 including the sensor face 118 move from the capturingposition toward the recessed position with the rear end part thereofmoving down.

Subsequently, the image sensor 108 and the sensor cover 110 includingthe sensor face 118 that have moved to the recessed position move andreturn from the recessed position to the capturing position with therear end part moving up, as illustrated in FIG. 9C. At the capturingposition after the return, the sensor face 118 again comes into contactwith the ball of the finger F.

Note that the CPU 166 of the fingerprint reading device 10 can usevarious triggers as a trigger for the switching from moving down tomoving up of the rear end part of the image sensor 108 and the sensorcover 110. For example, when the rear end part of the image sensor 108and the sensor cover 110 move down and separation of the sensor face 118from the finger F is detected, the CPU 166 can use this as a trigger anddrive the sensor drive unit 114 so as to move up the rear end part ofthe image sensor 108 and the sensor cover 110. That is, in response todetection of separation of the finger F from the sensor face 118 movingfrom the capturing position toward the recessed position, the sensordrive unit 114 moves the image sensor 108 and the sensor cover 110including the sensor face 118 toward the capturing position. Theseparation of the finger F from the sensor face 118 can be detectedbased on a change in an image captured by the image sensor 108, forexample, or can be detected by a sensor that can detect contact such asa touch sensor provided on the sensor face 118.

Further, when the user uses the motion switch 142 to manually move theimage sensor 108 and the sensor cover 110, the following configurationis possible. That is, such a configuration is possible in which anotherpress of the motion switch 142 causes the image sensor 108 and thesensor cover 110 including the sensor face 118 moving from the capturingposition toward the recessed position to change the moving direction andmove from the recessed position toward the capturing position. In thiscase, for example, in response to detecting the separation of the sensorface 118 from the finger F, the CPU 166 of the fingerprint readingdevice 10 or the CPU 202 of the image processing apparatus 20 notifiesthe user that the sensor face 118 has separated from the finger F byusing a notification light, a notification sound, a screen display, orthe like, for example. This enables the user to know the timing to moveup the image sensor 108 and the sensor cover 110 without requiring tomove down the whole of the image sensor 108 and the sensor cover 110.The user who has been notified of the separation of the sensor face 118from the finger F again presses the motion switch 142. Another press ofthe motion switch 142 causes the image sensor 108 and the sensor cover110 including the sensor face 118 to move from the recessed position,which is the position where the sensor face 118 that has separated fromthe finger F, toward the capturing position.

As discussed above, in the present example embodiment, the sensor face118 once separates from the ball of the finger F at the recessedposition. Subsequently, the sensor face 118 again comes into contactwith the ball of the finger F at the capturing position recovered fromthe recessed position. The sensor face 118 once separates from the ballof the finger F, which can reduce or even remove elastic deformation ofthe finger F generated at the first contact of the sensor face 118. Inthe present example embodiment, after elastic deformation of the fingerF is reduced or even removed in such a way, the fingerprint of thefinger F is captured and read, and a fingerprint image is acquired asdescribed below. Therefore, according to the present example embodiment,even when reading a fingerprint of the finger F which is relatively softand may be easily elastically deformed, it is possible to appropriatelyread the fingerprint and acquire a high quality fingerprint image. Whena fingerprint is read after elastic deformation that has occurred in thefinger F is reduced or the like, the read fingerprint as illustrated inFIG. 10C is substantially the same as the ideal fingerprint illustratedin FIG. 10A.

Further, in the present example embodiment, while the image sensor 108and the sensor cover 110 move from the capturing position to therecessed position and then return to the imaging position, the lightguiding parts 124 support the finger F. That is, meanwhile, the edgeparts 128 and parts of the protrusion parts 126, which correspond toportions of the light guiding parts 124 located extending over the endsof the sensor face 118 support the finger F from the sensor face 118side. Therefore, according to the present example embodiment, althoughthe sensor face 118 once separates from the ball of the finger F,displacement of the finger F can be suppressed or even prevented, andtherefore the fingerprint of the finger F can be read moreappropriately, and a higher quality fingerprint image can be acquired.

Japanese Patent Application Publication No. 2005-182474 discloses aconfiguration in which, in response to detection of a finger beingplaced on the placement portion, a fingerprint sensor is moved up to theplacement portion by a motor. In such a configuration, since thefingerprint sensor is located at a move-down position separated from theplacement portion at time other than the time of reading a fingerprint,it is difficult to secure air tightness inside the casing, and thusthere is a problem of dust resistance. In contrast, in the presentexample embodiment, the image sensor 108 and the sensor cover 110 arenormally positioned at the capturing position and seal the inside of theplacement portion 102 and, at the time of reading a fingerprint, arecaused to move from the capturing position to the recessed position andfurther move and return from the recessed position to the capturingposition. As discussed above, in the present example embodiment, sincethe image sensor 108 and the sensor cover 110 normally seal the insideof the placement portion 102, good dust resistance can be secured.

Next, in a state where the ball of the finger F is again in contact withthe sensor face 118 of the fingerprint reading device 10, the user maypress the capture switch 144. In response to this press of the captureswitch 144, a capture instruction signal is input to instruct thefingerprint reading device 10 of capturing.

In response to the capture instruction signal input by press of thecapture switch 144, the CPU 166 of the fingerprint reading device 10drives the image sensor 108 and turns on the side light sources 112.Thereby, the fingerprint reading device 10 captures and reads afingerprint of the finger F by using the image sensor 108 and acquires afingerprint image. After acquisition of a fingerprint image, the CPU 166of the fingerprint reading device 10 turns off the side light sources112.

Further, in response to acquiring a fingerprint image, the CPU 166 ofthe fingerprint reading device 10 transfers the image data of theacquired fingerprint image to the image processing apparatus 20 via thecommunication cable 30.

In the image processing apparatus 20 to which image data of afingerprint image has been transferred, after temporarily storing theimage data in the RAM 206 as the image memory, the CPU 202 performspredetermined image processing on image data. Furthermore, the CPU 202of the image processing apparatus 20 displays the fingerprint image onthe display 214. Further, the CPU 202 of the image processing apparatus20 records the fingerprint image in the HDD 208 or the like in responseto input of a recording instruction from the user or automatically.

Second Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto a second example embodiment of the present invention will bedescribed by using FIG. 11 to FIG. 13 . Note that the same components asthose in the fingerprint reading device according to the first exampleembodiment described above are labeled with the same references, and thedescription thereof will be omitted or simplified.

The basic configuration of the fingerprint reading device according tothe present example embodiment is substantially the same as theconfiguration of the fingerprint reading device 10 according to thefirst example embodiment described above. The fingerprint reading deviceaccording to the present example embodiment is different from thefingerprint reading device 10 according to the first example embodimentin the position where the image sensor 108 is attached to the casing 106and in a feature in which the image sensor 108 is supported and moveddown and up by the sensor drive unit 114.

The specific configuration of the fingerprint reading device accordingto the present example embodiment will be described below by using FIG.11 and FIG. 12 . FIG. 11 is a plan view illustrating the fingerprintreading device according to the present example embodiment, whichillustrates a plane viewed from the front face side out of the frontface and the back face of the fingerprint reading device. FIG. 12 is alongitudinal sectional view illustrating the fingerprint reading deviceaccording to the present example embodiment, which illustrates alongitudinal sectional view taken along a line A-A of FIG. 11 .

As illustrated in FIG. 11 and FIG. 12 , in a fingerprint reading device2010 according to the present example embodiment, unlike the firstexample embodiment, the rear end part of the image sensor 108 isattached to a top plate front end of the holding portion 104 in thecasing 106 via a hinge part 2120. The hinge part 2120 includes a rockingshaft extending in the width direction of the placement portion 102 inthe casing 106.

The image sensor 108 and the sensor cover 110 including the sensor face118 are provided so as to be swing about a rocking shaft of the hingepart 2120 located at the rear side end of the placement portion 102 as afulcrum. This enables the image sensor 108 and the sensor cover 110including the sensor face 118 to move between a capturing position,which is the first position, and a recessed position, which is thesecond position, located inside the casing 106 deeper than the capturingposition.

At the capturing position, the image sensor 108 and the sensor cover 110are arranged such that the sensor face 118 of the sensor cover 110 isorthogonal to the perpendicular direction of the placement portion 102as with the first example embodiment. The image sensor 108 and thesensor cover 110 positioned at the capturing position seal the inside ofthe placement portion 102 as with the first example embodiment. On theother hand, at the recessed position, in the present example embodiment,unlike the first example embodiment, the image sensor 108 and the sensorcover 110 are arranged such that the sensor face 118 of the sensor cover110 is inclined to face the frontward oblique upper direction of theplacement portion 102.

The image sensor 108 and the sensor cover 110 including the sensor face118 are driven by a sensor drive unit 2114 similar to the sensor driveunit 114 according to the first example embodiment and move between thecapturing position and the recessed position.

In FIG. 12 , the image sensor 108 and the sensor cover 110 at thecapturing position are illustrated by the solid line, and the imagesensor 108 and the sensor cover 110 at the recessed position areillustrated by the one-dot-chain line. As illustrated, the sensor face118 of the sensor cover 110 at the capturing position is orthogonal tothe perpendicular direction of the placement portion 102 and forms aflat face with the surface of the holding portion 104 with substantiallyno step in a similar manner to the first example embodiment. On theother hand, unlike the first example embodiment, the sensor face 118 ofthe sensor cover 110 at the recessed position is inclined so as to enterthe inside of the casing 106 in the direction from the rear side to thefront side of the placement portion 102.

The fingerprint reading device 2010 according to the present exampleembodiment has the sensor drive unit 2114 instead of the sensor driveunit 114 according to the first example embodiment. The sensor driveunit 2114 is provided under the front end part of the image sensor 108inside the casing 106 of the placement portion 102. The sensor driveunit 2114 has the same drive mechanism as that of the sensor drive unit114 according to the first example embodiment.

The sensor drive unit 2114 drives the front end part of the image sensor108, which is attached to the casing 106 so as to be able to swing, tomove up and down and causes the image sensor 108 and the sensor cover110 including the sensor face 118 to swing and move.

Specifically, the sensor drive unit 2114 causes the front end part ofthe image sensor 108 positioned at the capturing position to move downand causes the image sensor 108 and the sensor cover 110 including thesensor face 118 to swing and move from the capturing position to therecessed position. Further, the sensor drive unit 2114 causes the frontend part of the image sensor 108 positioned at the recessed position tomove up and causes the image sensor 108 and the sensor cover 110including the sensor face 118 to swing and move from the recessedposition to the capturing position. In such a way, the sensor drive unit2114 causes the image sensor 108 and the sensor cover 110 including thesensor face 118 to move from the capturing position to the recessedposition and further move and return from the recessed position to thecapturing position.

The configuration of the sensor drive unit 2114 is not limited to aparticular configuration as with the sensor drive unit 114 according tothe first example embodiment as long as it can move down and up thefront end part of the image sensor 108. For example, the sensor driveunit 2114 may have a solenoid-type configuration in which a solenoid isused as an actuator as with the sensor drive unit 114 according to thefirst example embodiment.

Next, the operation of the fingerprint reading device 2010 according tothe present example embodiment will be further described by using FIG.13A to FIG. 13C. FIG. 13A to FIG. 13C are schematic diagramsillustrating the operation of the fingerprint reading device 2010according to the present example embodiment. FIG. 13A to FIG. 13Cillustrate the positional relationship of the finger F with the imagesensor 108 and the sensor cover 110 while the finger F comes intocontact with the sensor face 118 and then a fingerprint is captured. Forsimplified illustration, the side light sources 112 are omitted in FIG.13A to FIG. 13C.

First, in a similar manner to the first example embodiment, in a statewhere the image sensor 108 and the sensor cover 110 including the sensorface 118 are positioned at the capturing position, the user causes theball of the finger F of the subject to come into contact with the sensorface 118 of the fingerprint reading device 2010, as illustrated in FIG.13A. In a state where the ball of the finger F is in contact with thesensor face 118, in a similar manner to the first example embodiment,the edge part 128 and a part of the protrusion part 126 in contact withthe surface of the finger F on the sensor face 118 side support thefinger F in contact with the sensor face 118.

Subsequently, in a state where the ball of the finger F is in contactwith the sensor face 118, the user presses the motion switch 142 in asimilar manner to the first example embodiment. With the motion switch142 being pressed, a drive instruction signal is input to instruct thefingerprint reading device 2010 to drive the image sensor 108 and thesensor cover 110.

The CPU 166 of the fingerprint reading device 2010 drives the sensordrive unit 2114 in response to the drive instruction signal input bypress of the motion switch 142 and drives the image sensor 108 and thesensor cover 110 including the sensor face 118. Thereby, the imagesensor 108 and the sensor cover 110 including the sensor face 118 swingabout a rocking shaft of the hinge part 2120 attached to the casing 106of the rear end part of the image sensor 108 as a fulcrum.

Note that, also in the present example embodiment, in a configurationwithout the motion switch 142 being provided in a similar manner to thefirst example embodiment. In this case, in response to detection ofcontact of the ball of the finger F with the sensor face 118, the driveinstruction signal is input, and the image sensor 108 and the sensorcover 110 are driven by the sensor drive unit 2114 in the same manner asdescribed above.

The image sensor 108 and the sensor cover 110 including the sensor face118 that start swinging first move from the capturing position to therecessed position with the front end part thereof moving down, asillustrated in FIG. 13B. At the recessed position, the sensor face 118separates from the ball of the finger F. In a configuration without themotion switch 142 being provided, in response to detection of contact ofthe ball of the finger F with the sensor face 118, the image sensor 108and the sensor cover 110 move from the capturing position toward therecessed position with the front end part thereof moving down.

Subsequently, the image sensor 108 and the sensor cover 110 includingthe sensor face 118 that have moved to the recessed position move andreturn from the recessed position to the capturing position with thefront end part moving up, as illustrated in FIG. 13C. At the capturingposition after the return, the sensor face 118 again comes into contactwith the ball of the finger F.

Note that the CPU 166 of the fingerprint reading device 2010 can usevarious triggers as a trigger for the switching from moving down tomoving up of the front end part of the image sensor 108 and the sensorcover 110. For example, when the front end part of the image sensor 108and the sensor cover 110 move down and separation of the sensor face 118from the finger F is detected, the CPU 166 can use this as a trigger anddrive the sensor drive unit 2114 to move up the front end part of theimage sensor 108 and the sensor cover 110. That is, in response todetection of separation of the finger F from the sensor face 118 movingfrom the capturing position toward the recessed position, the sensordrive unit 2114 moves the image sensor 108 and the sensor cover 110including the sensor face 118 toward the capturing position. Theseparation of the finger F from the sensor face 118 can be detected in asimilar manner to the first example embodiment.

Further, the present example embodiment may be configured such that, ina similar manner to the first example embodiment, another press of themotion switch 142 causes the image sensor 108 and the sensor cover 110including the sensor face 118 moving from the capturing position towardthe recessed position to change the moving direction and move from therecessed position toward the capturing position.

As discussed above, also in the present example embodiment, the sensorface 118 once separates from the ball of the finger F at the recessedposition. Subsequently, the sensor face 118 again comes into contactwith the ball of the finger F at the capturing position recovered fromthe recessed position. Thereby, also in the present example embodiment,elastic deformation of the finger F generated at the first contact tothe sensor face 118 can be reduced or even removed. Therefore, accordingto the present example embodiment, even when reading a fingerprint ofthe finger F which is relatively soft and may be easily elasticallydeformed, it is possible to appropriately read the fingerprint andacquire a high quality fingerprint image.

Further, in the present example embodiment, while the image sensor 108and the sensor cover 110 move from the capturing position to therecessed position and then return to the capturing position, the edgeparts 128 and parts of the protrusion parts 126 in the light guidingparts 124 support the finger F from the sensor face 118 side. Therefore,according to the present example embodiment, although the sensor face118 once separates from the ball of the finger F, displacement of thefinger F can be suppressed or even prevented, and therefore thefingerprint of the finger F can be read more appropriately, and a higherquality fingerprint image can be acquired.

Also in the present example embodiment, since the image sensor 108 andthe sensor cover 110 normally seal the inside of the placement portion102, good dust resistance can be secured in a similar manner to thefirst example embodiment.

Since the subsequent operation is the same as the first exampleembodiment, the description thereof will be omitted.

Note that, while the case where the front end part or the rear end partof the image sensor 108 is attached to the casing 106 via the hinge part2120 has been described in the above first and second exampleembodiments, a case is not limited thereto. For example, one of the sideend parts of the image sensor 108 may be attached so as to be able toswing to one of the side parts of the placement portion 102 in thecasing 106 via a hinge part. In such a case, the hinge part includes arocking shaft extending in the front-rear direction of the placementportion 102 in the casing 106, for example. Further, in such a case, asensor drive unit that drives the other side end part of the imagesensor 108 to move up and down, which is similar to the sensor driveunit 114, may be provided inside the placement portion 102.

Third Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto a third example embodiment of the present invention will be describedby using FIG. 14 to FIG. 17 . Note that the same components as those inthe fingerprint reading device and the fingerprint reading methodaccording to the first and second example embodiments described aboveare labeled with the same references, and the description thereof willbe omitted or simplified.

The basic configuration of the fingerprint reading device according tothe present example embodiment is substantially the same as theconfiguration of the fingerprint reading device 10 according to thefirst example embodiment described above. The fingerprint reading deviceaccording to the present example embodiment is different from thefingerprint reading device 10 according to the first example embodimentin a manner of motion of the image sensor 108 and the sensor cover 110.

The specific configuration of the fingerprint reading device accordingto the present example embodiment will be described below by using FIG.14 to FIG. 16B. FIG. 14 is a plan view illustrating the fingerprintreading device according to the present example embodiment, whichillustrates a plane viewed from the front face side out of the frontface and the back face of the fingerprint reading device. FIG. 15 is alongitudinal sectional view illustrating the fingerprint reading deviceaccording to the present example embodiment, which illustrates alongitudinal sectional view taken along a line A-A of FIG. 14 . FIG. 16Aand FIG. 16B are schematic diagram illustrating an example of a sensordrive unit in the fingerprint reading device according to the presentexample embodiment.

As illustrated in FIG. 14 and FIG. 15 , in a fingerprint reading device3010 according to the present example embodiment, unlike the firstexample embodiment, the image sensor 108 is attached to the bottominside the casing 106 of the placement portion 102 via a sensor driveunit 3114.

The image sensor 108 and the sensor cover 110 including the sensor face118 are able to parallelly shift in the perpendicular direction of thecasing 106 via the sensor drive unit 3114. The direction in which theimage sensor 108 and the sensor cover 110 are able to parallelly shiftis the direction orthogonal to the sensor face 118. This enables theimage sensor 108 and the sensor cover 110 including the sensor face 118to move between a capturing position, which is the first position, and arecessed position, which is the second position, located inside thecasing 106 deeper than the capturing position. In the present exampleembodiment, unlike the first example embodiment, also at the recessedposition, the image sensor 108 and the sensor cover 110 are notinclined, and the sensor face 118 of the sensor cover 110 remainsorthogonal to the perpendicular direction of the casing 106. Note thatthe image sensor 108 and the sensor cover 110 positioned at thecapturing position seal the inside of the placement portion 102 in asimilar manner to the first example embodiment.

The image sensor 108 and the sensor cover 110 including the sensor face118 are driven by the sensor drive unit 3114 and move between thecapturing position and the recessed position.

In FIG. 15 , the image sensor 108 and the sensor cover 110 at thecapturing position are illustrated by the solid line, and the imagesensor 108 and the sensor cover 110 at the recessed position areillustrated by the one-dot-chain line. As illustrated, the sensor face118 of the sensor cover 110 at the capturing position is orthogonal tothe perpendicular direction of the placement portion 102 and forms aflat face with the surface of the holding portion 104 with substantiallyno step in a similar manner to the first example embodiment. On theother hand, the sensor face 118 of the sensor cover 110 at the recessedposition is located inside the casing 106 deeper than when positioned atthe capturing position and remains orthogonal to the perpendiculardirection of the placement portion 102.

The fingerprint reading device 3010 according to the present exampleembodiment has the sensor drive unit 3114 instead of the sensor driveunit 114 according to the first example embodiment. The sensor driveunit 3114 is provided under the center part of the image sensor 108 inthe casing 106 of the placement portion 102. The image sensor 108 isattached on the top of the sensor drive unit 3114.

The sensor drive unit 3114 drives the image sensor 18 attached on thetop thereof to move down and up and parallelly shifts the image sensor108 and the sensor cover 110.

Specifically, the sensor drive unit 3114 causes the entire image sensor108 positioned at the capturing position to move down and thereby theimage sensor 108 and the sensor cover 110 including the sensor face 118to parallelly shift from the capturing position to the recessedposition. Further, the sensor drive unit 3114 causes the entire imagesensor 108 positioned at the recessed position to move up and therebythe image sensor 108 and the sensor cover 110 including the sensor face118 to parallelly shift from the recessed position to the capturingposition. In such a way, the sensor drive unit 3114 causes the imagesensor 108 and the sensor cover 110 including the sensor face 118 tomove from the capturing position to the recessed position and furthermove and return from the recessed position to the capturing position.

The configuration of the sensor drive unit 3114 is not limited to aparticular configuration, and any configuration that can move down andup the entire image sensor 108 may be employed. For example, the sensordrive unit 3114 may have a pantograph-type configuration in which apantograph mechanism is used. FIG. 16A and FIG. 16B illustrate onehaving a pantograph-type configuration as an example of the sensor driveunit 3114. FIG. 16A is a side view illustrating the pantograph-typesensor drive unit 3114 when the image sensor 108 is positioned at thecapturing position. FIG. 16B is a side view illustrating thepantograph-type sensor drive unit 3114 when the image sensor 108 ispositioned at the recessed position.

As illustrated in FIG. 16A and FIG. 16B, the pantograph-type sensordrive unit 3114 has a base 3116, a pantograph mechanism includingpantograph arms 3118, and a support part 3120. Note that two pantographarms 3118 are provided adjacently in parallel, for example. Further, thepantograph-type sensor drive unit 3114 has a drive mechanism 3122 thatdrives the pantograph arms 3118.

The base 3116 is provided on the bottom inside the casing 106 in theplacement portion 102. The support part 3120 is provided above the base3116 via the pantograph arms 3118. The drive mechanism 3122 is providedon the base 3116.

One end and the other end on the lower side of the pantograph arms 3118are pivotally supported on the base 3116. One of the one end and theother end on the lower side of the pantograph arm 3118 is slidable alongthe base 3116. One end and the other end on the upper side of thepantograph arms 3118 are pivotally supported on the support part 3120.One of the one end and the other end on the upper side of the pantographarm 3118 is slidable along the support part 3120.

The drive mechanism 3122 drives one end on the lower side of thepantograph arms 3118 to slide. The drive mechanism 3122 is not limitedto a particular mechanism, and may be a mechanism that performselectrical slide driving or may be a mechanism that performs mechanicalslide driving. For example, as the drive mechanism 3122, an electricaldrive mechanism that drives one end on the lower side of the pantographarms 3118 to slide by using a ball screw rotated by a drive motor, asolenoid, or the like can be used. Further, as the drive mechanism 3122,a mechanical drive mechanism that drives one end on the lower side ofthe pantograph arms 3118 to slide by using a manually operated lever orthe like can be used, for example.

The pantograph arms 3118 expand and contract in the perpendiculardirection of the casing 106 by one end on the lower side thereof beingdriven by the drive mechanism 3122 and sliding. That is, the pantographarms 3118 expand by one end on the lower side thereof being driven bythe drive mechanism 3122 and sliding so that one end on the lower sidethereof approaches the other end. Further, the pantograph arms 3118contract by one end on the lower side thereof being driven by the drivemechanism 3122 and sliding so that one end on the lower side thereofseparates from the other end.

The image sensor 108 is attached to the support part 3120. The imagesensor 108 and the sensor cover 110 are supported so that the sensorface 118 is orthogonal to the perpendicular direction of the casing 106.

As illustrated in FIG. 16A, in a state where the pantograph arms 3118have expanded, the image sensor 108 and the sensor cover 110 includingthe sensor face 118 supported by the support part 3120 are positioned atthe capturing position.

As illustrated in FIG. 16B, when the pantograph arms 3118 aretransferred from the expansion state to the contraction state by thedrive mechanism 3122, the image sensor 108 and the sensor cover 110including the sensor face 118 supported by the support part 3120 movedown from the capturing position. Thereby, the image sensor 108 and thesensor cover 110 including the sensor face 118 move to the recessedposition.

Furthermore, when the pantograph arms 3118 are transferred from thecontraction state to the expansion state by the drive mechanism 3122,the image sensor 108 and the sensor cover 110 including the sensor face118 supported by the support part 3120 move and return from the recessedposition to the capturing position.

In such a way, the pantograph-type sensor drive unit 3114 moves down andup the whole of the image sensor 108 and the sensor cover 110 by usingthe pantograph arms 3118. Thereby, the sensor drive unit 3114 causes theimage sensor 108 and the sensor cover 110 to parallelly shift andthereby the image sensor 108 and the sensor cover 110 including thesensor face 118 to move between the capturing position and the recessedposition.

As described above, a pantograph-type one having a pantograph mechanismcan be used as the sensor drive unit 3114.

Next, the operation of the fingerprint reading device 3010 according tothe present example embodiment will be further described by using FIG.17A to FIG. 17C. FIG. 17A to FIG. 17C are schematic diagramsillustrating the operation of the fingerprint reading device 3010according to the present example embodiment. FIG. 17A to FIG. 17Cillustrate the positional relationship of the finger F with the imagesensor 108 and the sensor cover 110 after the finger F comes intocontact with the sensor face 118 and before a fingerprint is captured.For simplified illustration, the side light sources 112 are omitted inFIG. 17A to FIG. 17C.

First, in a similar manner to the first example embodiment, in a statewhere the image sensor 108 and the sensor cover 110 including the sensorface 118 are positioned at the capturing position, the user causes theball of the finger F of a subject to come into contact with the sensorface 118 of the fingerprint reading device 3010, as illustrated in FIG.17A. In a state where the ball of the finger F is in contact with thesensor face 118, in the same manner as the first example embodiment, theedge parts 128 and parts of the protrusion parts 126 in contact with thesurface of the finger F on the sensor face 118 side support the finger Fin contact with the sensor face 118 from the sensor face 118 side.

Next, in a state where the ball of the finger F is in contact with thesensor face 118, the user presses the motion switch 142 in the similarmanner to the first example embodiment. With the motion switch 142 beingpressed, a drive instruction signal is input to instruct the fingerprintreading device 3010 to drive the image sensor 108 and the sensor cover110.

The CPU 166 of the fingerprint reading device 3010 drives the sensordrive unit 3114 in response to the drive instruction signal input bypress of the motion switch 142 and drives the image sensor 108 and thesensor cover 110 including the sensor face 118. Thereby, the imagesensor 108 and the sensor cover 110 including the sensor face 118parallelly shift in the perpendicular direction of the casing 106.

Note that, also in the present example embodiment, a configurationwithout the motion switch 142 being provided is possible in a similarmanner to the first example embodiment. In this case, in response todetection of contact of the ball of the finger F with the sensor face118, the drive instruction signal is input, and the image sensor 108 andthe sensor cover 110 are driven by the sensor drive unit 3114 in thesame manner as described above.

The image sensor 108 and the sensor cover 110 including the sensor face118 that starts parallelly shifting first move down as a whole and movefrom the capturing position to the recessed position, as illustrated inFIG. 17B. At the recessed position, the sensor face 118 separates fromthe ball of the finger F. In the configuration without the motion switch142 being provided, in response to detection of the contact of the ballof the finger F with the sensor face 118, the image sensor 108 and thesensor cover 110 move down as a whole and move from the capturingposition toward the recessed position.

Subsequently, the image sensor 108 and the sensor cover 110 includingthe sensor face 118 that have moved to the recessed position move up asa whole and move and return from the recessed position to the capturingposition, as illustrated in FIG. 17C. At the capturing position afterthe return, the sensor face 118 again comes into contact with the ballof the finger F.

Note that the CPU 166 of the fingerprint reading device 3010 can usevarious triggers as a trigger for the switching from moving down tomoving up of the whole of the image sensor 108 and the sensor cover 110.For example, when the whole of the image sensor 108 and the sensor cover110 move down and separation of the sensor face 118 from the finger F isdetected, the CPU 166 can use this detection as a trigger and drive thesensor drive unit 3114 so as to move up the whole of the image sensor108 and the sensor cover 110. That is, in response to detection ofseparation of the finger F from the sensor face 118 moving from thecapturing position toward the recessed position, the sensor drive unit3114 moves the image sensor 108 and the sensor cover 110 including thesensor face 118 toward the capturing position. The separation of thefinger F from the sensor face 118 can be detected in a similar manner tothe first example embodiment.

Further, the present example embodiment can be also configured suchthat, in a similar manner to the first example embodiment, another pressof the motion switch 142 causes the image sensor 108 and the sensorcover 110 including the sensor face 118 moving from the capturingposition toward the recessed position to change the moving direction andmove from the recessed position toward the capturing position.

As discussed above, also in the present example embodiment, the sensorface 118 once separates from the ball of the finger F at the recessedposition. Subsequently, the sensor face 118 again comes into contactwith the ball of the finger F at the capturing position recovered fromthe recessed position. Thereby, also in the present example embodiment,elastic deformation of the finger F generated at the first contact tothe sensor face 118 can be reduced or even removed. Therefore, accordingto the present example embodiment, even when reading a fingerprint ofthe finger F which is relatively soft and may be easily elasticallydeformed, it is possible to appropriately read the fingerprint andacquire a high quality fingerprint image.

Further, in the present example embodiment, while the image sensor 108and the sensor cover 110 move from the capturing position to therecessed position and then return to the imaging position, the edgeparts 128 and parts of the protrusion parts 126 in the light guidingparts 124 support the finger F from the sensor face 118 side. Therefore,according to the present example embodiment, although the sensor face118 once separates from the ball of the finger F, displacement of thefinger F can be suppressed, and therefore the fingerprint of the fingerF can be read more appropriately, and a higher quality fingerprint imagecan be acquired.

Also in the present example embodiment, since the image sensor 108 andthe sensor cover 110 normally seal the inside of the placement portion102, good dust resistance can be secured in a similar manner to thefirst example embodiment.

Since the subsequent operation is the same as the first exampleembodiment, the description thereof will be omitted.

Fourth Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto a fourth example embodiment of the present invention will bedescribed by using FIG. 18 . Note that the same components as those inthe fingerprint reading device and the fingerprint reading methodaccording to the first to third example embodiments described above arelabeled with the same references, and the description thereof will beomitted or simplified.

The basic configuration of the fingerprint reading device according tothe present example embodiment is substantially the same as theconfiguration of the fingerprint reading device 10 according to thefirst example embodiment described above. The fingerprint reading deviceaccording to the present example embodiment is different from thefingerprint reading device 10 according to the first example embodimentin the shape of light guiding parts in the side light sources 112.

The specific configuration of the fingerprint reading device accordingto the present example embodiment will be described below by using FIG.18 . FIG. 18 is a plan view illustrating the fingerprint reading deviceaccording to the present example embodiment, which illustrates a planecorresponding to the plane of the fingerprint reading device 10according to the first example embodiment illustrated in FIG. 2 .

As illustrated in FIG. 18 , in a fingerprint reading device 4010according to the present example embodiment, each of the pair of sidelight sources 112 has a light guiding part 4124 instead of the lightguiding part 124 according to the first example embodiment. Note thatthe light-transmitting material of the light guiding parts 4124 is thesame as that of the light guiding parts 124 according to the firstexample embodiment.

The light guiding part 4124 in each side light source 112 is formedextending in the front-rear direction of the placement portion 102 in asimilar manner to the light guiding part 124 according to the firstexample embodiment. The light guiding part 4124 has a ridge-likeprotrusion part 4126 and a skirt-like edge part 4128. The protrusionpart 4126 is the same as the protrusion part 126 according to the firstexample embodiment.

The edge part 4128 is formed in a skirt-like manner integrally with theprotrusion part 4126 so as to extend on the sensor face 118 side of theprotrusion part 4126 continuously from the protrusion part 4126 on thesensor face 118 side in a similar manner to the edge part 128 accordingto the first example embodiment. The edge part 4128 has a lower heightin the perpendicular direction of the placement portion 102 than theprotrusion part 4126, and the height thereof gradually decreases towardthe sensor face 118 side. A part of the protrusion part 4126 on the edgepart 4128 side and the edge part 4128 are located protruding over theend of the sensor face 118 in the same manner as in the first exampleembodiment.

Furthermore, unlike the edge part 128 according to the first exampleembodiment, the edge part 4128 has a portion whose protruding width,which is a width located over the end of the sensor face 118, is notconstant. Specifically, in the front side part of the placement portion102, the edge part 4128 has an increasing protruding width thereoftoward the front side of the placement portion 102 in the front-reardirection of the placement portion 102. Thus, the spacing between theedge part 4128 of one of the side light sources 112 and the edge part4128 of the other side light source 112 is narrower toward the frontside of the placement portion 102 in the front-rear direction of theplacement portion 102.

As discussed above, in the fingerprint reading device 4010 according tothe present example embodiment, with a portion having wider protrudingwidths of the edge parts 4128 in the front side part of the placementportion 102 as described above, it is possible to more tightly support afinger whose fingerprint is to be read from the sensor face 118 side.Thus, according to the present example embodiment, it is possible tofurther ensure to suppress displacement of a finger whose fingerprint isto be read. Further, the portion having a wider protruding width of theedge part 4128 is located in the front side part of the placementportion 102 and thus does not prevent capturing of a fingerprintperformed by the image sensor 108. Therefore, according to the presentexample embodiment, the fingerprint can be read more appropriately, anda higher quality fingerprint image can be acquired.

Further, the tip part of a finger has a more feature amount of afingerprint than the root part of the finger. Thus, in the presentexample embodiment, as illustrated in FIG. 18 , although the edge parts4128 corresponding to the root part of a finger is present, since a partcorresponding to the tip part of the finger is opened, the tip part ofthe finger is able to come into contact with the sensor face 118, and afingerprint image can be acquired.

Note that, while a case where the light guiding parts 4124 are providedinstead of the light guiding parts 124 in the first example embodimenthas been described above, the light guiding parts 4124 may be providedinstead of the light guiding part 124 also in the second and thirdexample embodiments.

Fifth Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto a fifth example embodiment of the present invention will be describedby using FIG. 19 . Note that the same components as those in thefingerprint reading device and the fingerprint reading method accordingto the first to fourth example embodiments described above are labeledwith the same references, and the description thereof will be omitted orsimplified.

The basic configuration of the fingerprint reading device according tothe present example embodiment is substantially the same as theconfiguration of the fingerprint reading device 10 according to thefirst example embodiment described above. The fingerprint reading deviceaccording to the present example embodiment is different from thefingerprint reading device 10 according to the first example embodimentin the shape of light guiding parts in the side light sources 112.

The specific configuration of the fingerprint reading device accordingto the present example embodiment will be described below by using FIG.19 . FIG. 19 is a plan view illustrating the fingerprint reading deviceaccording to the present example embodiment, which illustrates a planecorresponding to the plane of the fingerprint reading device 10according to the first example embodiment illustrated in FIG. 2 .

As illustrated in FIG. 19 , in a fingerprint reading device 5010according to the present example embodiment, each of the pair of sidelight sources 112 has a light guiding part 5124 instead of the lightguiding part 124 according to the first example embodiment. Note thatthe light-transmitting material of the light guiding parts 5124 is thesame as that of the light guiding parts 124 according to the firstexample embodiment.

The light guiding part 5124 in each side light source 112 is formedextending in the front-rear direction of the placement portion 102 in asimilar manner to the light guiding part 124 according to the firstexample embodiment. The light guiding part 5124 has a ridge-likeprotrusion part 5126 and a skirt-like edge part 5128. The protrusionpart 5126 is the same as the protrusion part 126 according to the firstexample embodiment.

The edge part 5128 is formed in a skirt-like manner integrally with theprotrusion part 5126 so as to extend on the sensor face 118 side of theprotrusion part 5126 continuously from the protrusion part 5126 on thesensor face 118 side in a similar manner to the edge part 128 accordingto the first example embodiment. The edge part 5128 has a lower heightin the perpendicular direction of the placement portion 102 than theprotrusion part 5126, and the height thereof gradually decreases towardthe sensor face 118 side. A part of the protrusion part 5126 on the edgepart 5128 side and the edge part 5128 are located protruding over theend of the sensor face 118 in the same manner as in the first exampleembodiment.

Furthermore, in the present example embodiment, the edge part 5128 ofone of the side light sources 112 and the edge part 5128 of the otherside light source 112 are formed to extend across the sensor face 118and be continuous to each other across the sensor face 118. The samelight shielding parts 130 as those in the first example embodiment areformed on the underside of the edge parts 5128 extending over the sensorface 118.

An opening 5130 that exposes the sensor face 118 is formed in the centerpart of the edge parts 5128 extending across the sensor face 118. Theopening 5130 is formed such that a part of the sensor face 118 of theshape and the area by which a fingerprint can be read is exposed whenthe image sensor 108 and the sensor cover 110 are positioned at thecapturing position. The planar shape of the opening 5130 is notparticularly limited but may be an ellipse or a shape of a fingertip,for example.

As discussed above, in the fingerprint reading device 5010 according tothe present example embodiment, with a portion other than the opening5130 of the edge parts 5128 extending across the sensor face 118 asdescribed above, it is possible to more tightly support a finger whosefingerprint is to be read from the sensor face 118 side. Thus, accordingto the present example embodiment, it is possible to further ensure tosuppress displacement of a finger whose fingerprint is to be read.Further, since the image sensor 108 is able to capture a fingerprintthrough the opening 5130, capturing of a fingerprint performed by theimage sensor 108 is not prevented. Therefore, according to the presentexample embodiment, the fingerprint can be read more appropriately, anda higher quality fingerprint image can be acquired.

Further, also in the present example embodiment, as illustrated in FIG.19 , although the edge parts 5128 corresponding to the root part of afinger is present, since a part corresponding to the tip part of afinger having a large feature amount of the fingerprint is opened, thetip part of the finger is able to come into contact with the sensor face118, and a fingerprint image can be acquired.

Note that, while a case where the light guiding parts 5124 are providedinstead of the light guiding parts 124 in the first example embodimenthas been described above, the light guiding parts 5124 may be providedinstead of the light guiding part 124 also in the second and thirdexample embodiments.

Sixth Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto a sixth example embodiment of the present invention will be describedby using FIG. 20 . Note that the same components as those in thefingerprint reading device and the fingerprint reading method accordingto the first to fifth example embodiments described above are labeledwith the same references, and the description thereof will be omitted orsimplified.

While the case where a newborn, an infant, or a young child is a subjectwhose fingerprint is to be read has been described in the above first tofifth example embodiments, a subject is not limited to a newborn, aninfant, and a young child. The fingerprint reading device can be appliedto persons of any age group as a subject in addition to a newborn, aninfant, and a young child.

In the present example embodiment, a case where the fingerprint readingdevice is applied not only to a newborn, an infant, and a young childbut also to persons other than a newborn, an infant, and a young childas a subject will be described. Note that persons other than a newborn,an infant, and a young child include an adult and a minor other than anewborn, an infant, and a young child. In the following description, anewborn, an infant, and a young child are denoted as “newborn or thelike”, and persons other than a newborn, an infant, and a young childare denoted as “adult or the like”.

The basic configuration of the fingerprint reading device according tothe present example embodiment that is applied to a newborn or the likeand an adult or the like as a subject is substantially the same as theconfiguration of the fingerprint reading device 10 according to thefirst example embodiment. Since the fingerprint reading device accordingto the present example embodiment is different from the fingerprintreading device 10 according to the first example embodiment in the shapeof light guiding parts in the side light sources 112 because an adult orthe like may also be a subject.

The specific configuration of the fingerprint reading device accordingto the present example embodiment will be described below by using FIG.20 . FIG. 20 is a transverse sectional view illustrating a fingerprintreading device according to the present example embodiment, whichillustrates a horizontal cross section corresponding to the horizontalcross section of the fingerprint reading device 10 according to thefirst example embodiment illustrated in FIG. 4 . Note that, in FIG. 20 ,the light guiding parts 124 according to the first example embodimentare illustrated by one-dot-chain lines for the purpose of comparison.

As illustrated in FIG. 20 , in a fingerprint reading device 6010according to the present example embodiment, each of the pair of sidelight sources 112 has a light guiding part 6124 instead of the lightguiding part 124 according to the first example embodiment. Note thatthe light-transmitting material of the light guiding parts 6124 is thesame as that of the light guiding parts 124 according to the firstexample embodiment.

The light guiding part 6124 in each of the side light sources 112 isformed extending in the front-rear direction of the placement portion102 in a similar manner to the light guiding part 124 according to thefirst example embodiment. The light guiding part 6124 has a ridge-likeprotrusion part 6126 and a skirt-like edge part 6128.

The protrusion part 6126 is formed in a ridge-like manner so as to coverthe plurality of near-infrared LEDs 122 and protrude above the top faceof the casing 106 in a similar manner to the protrusion part 126according to the first example embodiment. Unlike the protrusion part126 according to the first example embodiment, however, the protrusionpart 6126 is formed to neither protrude over the end of the sensor face118 nor be located over the end of the sensor face 118.

The edge part 6128 is formed in a skirt-like manner integrally with theprotrusion part 6126 so as to extend on the sensor face 118 side of theprotrusion part 6126 continuously from the protrusion part 6126 on thesensor face 118 side in a similar manner to the edge part 128 accordingto the first example embodiment. The edge part 6128 has a lower heightin the perpendicular direction of the placement portion 102 than theprotrusion part 6126, and the height thereof gradually decreases towardthe sensor face 118 side. In the present example embodiment, a part ofthe edge part 6128 is located protruding over the end of the sensor face118.

Each light shielding part 130 is provided on the underside of the sensorface 118 of a part of the edge parts 6128, which is a portion locatedprotruding over the end of the sensor face 118 of the light guiding part6124 in a similar manner to the first example embodiment.

Note that the protruding width, which is a width located over the end ofthe sensor face 118 that is a protruding part of the edge part 6128 canbe appropriately set to be able to read not only a finger of a newbornor the like but also a fingerprint of an adult or the like.

As discussed above, in the present example embodiment, the protrusionpart 6126 does not protrude over the end of the sensor face 118, andonly a part of the edge part 6128 of the light guiding part 6124 isprotruded and located over the end of the sensor face 118. Thus, in thepresent example embodiment, since a wider space is secured above thesensor face 118 compared to the first example embodiment, a finger of anadult or the like that is larger than a finger of a newborn or the likecan come into contact with the sensor face 118. Thereby, in the presentexample embodiment, not only a fingerprint of a newborn or the like butalso a fingerprint of an adult or the like can be read in a similarmanner to the first example embodiment.

Note that, when a fingerprint of an adult or the like as a subject isread, the subject of the adult or the like is able to operate thefingerprint reading device 6010 by himself/herself to have thefingerprint of his/her own finger read. In such a case, the subject isable to cause the ball of a finger whose fingerprint is to be capturedto come into contact with the sensor face 118 of the sensor cover 110while holding the holding portion 104 by a hand opposite to the handincluding a finger whose fingerprint is to be captured. The subject isable to hold the holding portion 104 from the sides such that, out offingers holding the holding portion 104, the thumb is located on the topplate side of the casing 106 and four fingers of the hand other than thethumb are located on the bottom plate side of the casing 106, forexample.

The subject of an adult or the like holding the holding portion 104 isable to press the motion switch 142 and the capture switch 144 by usingany of the four fingers located on the bottom plate side of the casing106 out of the fingers of the hand holding the holding portion 104 whileholding the holding portion 104. By a subject operating the motionswitch 142 and the capture switch 144 by himself/herself, a fingerprintof the subject can be read in a similar manner to the first exampleembodiment. Also when a fingerprint of a finger of an adult or the likeis read, the finger may be significantly elastically deformed due toinfluence of a moisture state, a high water-retention capability, a highmoisture percentage, or the like, for example. According to the presentexample embodiment, also when a fingerprint of a finger of an adult orthe like is read, since the fingerprint is read after elasticdeformation occurring in the finger is reduced or even removed in asimilar manner to the first example embodiment, the fingerprint can beread more appropriately, and a higher quality fingerprint image can beacquired.

However, when a fingerprint of a newborn or the like as a subject isread, the fingerprint of the subject can be read in the same manner asthe first example embodiment.

Note that, while a case where the light guiding parts 6124 are providedinstead of the light guiding parts 124 in the first example embodimenthas been described above, the light guiding parts 6124 may be providedinstead of the light guiding part 124 also in the second and thirdexample embodiments.

Further, also in the fourth and fifth example embodiments, the lightguiding parts 4124 or 5124 can be formed such that the protrusion parts4126 or 5126 are not located over the end of the sensor face 118 in asimilar manner to the present example embodiment.

Seventh Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto a seventh example embodiment of the present invention will bedescribed by using FIG. 21 . Note that the same components as those inthe fingerprint reading device and the fingerprint reading methodaccording to the first to sixth example embodiments described above arelabeled with the same references, and the description thereof will beomitted or simplified.

While a case where the image sensor 108 and the sensor cover 110including the sensor face 118 are provided so as to swing by using thehinge part 120 has been described in the above first example embodiment,the case is not limited thereto. The image sensor 108 and the sensorcover 110 including the sensor face 118 may be fixed and provided to theplacement portion 102 in the casing 106 so as to be positioned at thecapturing position.

In the present example embodiment, a case where the image sensor 108 andthe sensor cover 110 including the sensor face 118 are fixed andprovided to the placement portion 102 so as to be positioned at thecapturing position will be described.

The basic configuration of the fingerprint reading device according tothe present example embodiment is substantially the same as thefingerprint reading device 10 according to the first example embodiment.The fingerprint reading device according to the present exampleembodiment is different from the fingerprint reading device 10 accordingto the first example embodiment in that the image sensor 108 and thesensor cover 110 including the sensor face 118 are fixed and that thesensor drive unit 114 is not provided accordingly.

The specific configuration of the fingerprint reading device accordingto the present example embodiment will be described below by using FIG.21 . FIG. 21 is a longitudinal sectional view illustrating thefingerprint reading device according to the present example embodimentand illustrates a vertical cross section corresponding to the verticalcross section of the fingerprint reading device 10 according to thefirst example embodiment illustrated in FIG. 3 .

As illustrated in FIG. 21 , unlike the first example embodiment, thehinge part 120 is not used in a fingerprint reading device 7010according to the present example embodiment, and the image sensor 108 isfixed to the placement portion 102 in the casing 106 via a fixing member7116, for example. The fixing member 7116 fixes the image sensor 108 tothe bottom inside the placement portion 102. The image sensor 108 andthe sensor cover 110 including the sensor face 118 fixed to theplacement portion 102 are positioned at same the capturing position asthat in the first example embodiment. Note that the scheme of fixing theimage sensor 108 and the sensor cover 110 including the sensor face 118is not particularly limited, various schemes may be used for fixing.

As discussed above, in the present example embodiment, the image sensor108 and the sensor cover 110 including the sensor face 118 are fixed andprovided to the placement portion 102 so as to be positioned at thecapturing position. Note that, since the image sensor 108 and the sensorcover 110 are fixed, the sensor drive unit 114 is not provided in thepresent example embodiment.

As illustrated in the present example embodiment, the image sensor 108and the sensor cover 110 including the sensor face 118 may be fixed andprovided to the placement portion 102 so as to be positioned at thecapturing position.

Eighth Example Embodiment

A fingerprint reading device and a fingerprint reading method accordingto an eighth example embodiment of the present invention will bedescribed by using FIG. 22 . Note that the same components as those inthe fingerprint reading device and the fingerprint reading methodaccording to the first to seventh example embodiments described aboveare labeled with the same references, and the description thereof willbe omitted or simplified.

While the case where a user or a subject presses the motion switch 142and the capture switch 144 to have a fingerprint read has been describedin the above first to seventh example embodiments, reading of afingerprint can be automatically performed. In the present exampleembodiment, a case where reading of a fingerprint is automaticallyperformed will be described in the first example embodiment.

In the present example embodiment, the image processing apparatus 20 inthe fingerprint reading system 1 is configured to automate reading of afingerprint performed by the fingerprint reading device 10. In thepresent example embodiment, the image processing apparatus 20 and thefingerprint reading device 10 are formed as described below.

In the image processing apparatus 20, the CPU 202 functions as a controlunit that controls the operation of the fingerprint reading device 10including the sensor drive unit 114 and the image sensor 108 andautomates reading of a fingerprint performed by the fingerprint readingdevice 10. In response to a read instruction signal that is aninstruction to read a fingerprint, the CPU 202 outputs a control signalused for controlling the fingerprint reading device 10 and inputs thecontrol signal to the fingerprint reading device 10 via thecommunication cable 30. The control signal is a signal used forautomating reading of a fingerprint performed by the fingerprint readingdevice 10. The control signal includes a drive instruction signal thatis an instruction to drive the image sensor 108 and the sensor cover 110and a capture instruction signal that is an instruction to capture afingerprint after driving the image sensor 108 and the sensor cover 110.

The fingerprint reading device 10 and the image processing apparatus 20can be configured such that, in response to the user pressing thecapture switch 144, for example, the read instruction signal that is aninstruction to read a fingerprint described above is input to the imageprocessing apparatus 20 via the fingerprint reading device 10. Further,the image processing apparatus 20 may be configured such that, inresponse to the user operating the input device 218, the readinstruction signal that is an instruction to read a fingerprintdescribed above is input.

Furthermore, in the image processing apparatus 20, the CPU 202 functionsas a determination unit that determines the quality of a fingerprintimage transferred from the fingerprint reading device 10. The CPU 202determines the quality of the fingerprint image transferred from thefingerprint reading device 10 based on a criterion regarding thefingerprint image quality. The CPU 202 determines that the quality ofthe fingerprint image is good if the quality of the fingerprint image ishigher than or equal to a predetermined quality and determines that thequality of the fingerprint image is not good if the quality of thefingerprint image is lower than the predetermined quality.

If the CPU 202 determines that the quality of the fingerprint image isnot good, the CPU 202 again outputs a control signal including a driveinstruction signal and a capture instruction signal described above andinputs the control signal to the fingerprint reading device 10. In sucha way, the CPU 202 functions as a control unit that controls theoperation of the sensor drive unit 114 in accordance with the driveinstruction signal based on the determination result on the quality ofthe fingerprint image and controls the operation of the image sensor 108in accordance with the capture instruction signal.

On the other hand, in the fingerprint reading device 10, the CPU 166drives the sensor drive unit 114 and the image sensor 108 based on thecontrol signal input from the image processing apparatus 20.Specifically, the CPU 166 drives the sensor drive unit 114 in accordancewith the drive instruction signal that is an instruction to drive theimage sensor 108 and the sensor cover 110 included in the controlsignal. Thereby, the image sensor 108 and the sensor cover 110 includingthe sensor face 118 move from the capturing position to the recessedposition and further move and return from the recessed position to thecapturing position in the same manner as in the first exampleembodiment. Further, the CPU 166 causes the image sensor 108 to captureand read a fingerprint with the side light sources 112 being turned onin the same manner as in the first example embodiment in accordance withthe capture instruction signal included in the control signal, which isan instruction to capture a fingerprint after driving the image sensor108 and the sensor cover 110.

The operation of the fingerprint reading device 10 and the imageprocessing apparatus 20 according to the present example embodiment willbe described below by using FIG. 22 . FIG. 22 is a flowchartillustrating the operation of the fingerprint reading device and theimage processing apparatus according to the present example embodiment.

First, in the same manner as in the first example embodiment, the usercauses the ball of a finger of a subject to come into contact with thesensor face 118 of the fingerprint reading device 10 in a state wherethe image sensor 108 and the sensor cover 110 including the sensor face118 are positioned at the capturing position (step S102).

Next, the user inputs, to the image processing apparatus 20, a readinstruction signal that is an instruction to read a fingerprint by usingthe input device 218, for example (step S202).

Next, the CPU 202 of the image processing apparatus 20 outputs a controlsignal that controls the fingerprint reading device 10 and inputs thecontrol signal to the fingerprint reading device 10 in accordance withread instruction signal input by the user (step S204). The controlsignal includes a drive instruction signal that is an instruction todrive the image sensor 108 and the sensor cover 110 and a captureinstruction signal that is an instruction to capture a fingerprint afterdriving the image sensor 108 and the sensor cover 110. Note that, alsoin the present example embodiment, in the same manner as theconfiguration without the motion switch 142 being provided, the driveinstruction signal and the capture instruction signal may be input tothe fingerprint reading device 10 in the same manner as described abovebefore the read instruction signal is input by the user in response todetection of contact the ball of the finger with the sensor face 118.

Next, the CPU 166 of the fingerprint reading device 10 drives the sensordrive unit 114 as described below based on the control signal input fromthe image processing apparatus 20 and then causes the image sensor 108to capture a fingerprint (steps S104 and S106).

First, the CPU 166 drives the sensor drive unit 114 in accordance withthe drive instruction signal included in the control signal input fromthe image processing apparatus 20 (step S104). Thereby, the image sensor108 and the sensor cover 110 including the sensor face 118 move from thecapturing position to the recessed position and further move and returnfrom the recessed position to the capturing position in the same manneras in the first example embodiment. Note that, also in the presentexample embodiment, the same trigger as that in the first exampleembodiment can be used as a trigger by which the rear end part of theimage sensor 108 and the sensor cover 110 is switched from moving downto moving up.

Next, the CPU 166 causes the image sensor 108 to capture and read afingerprint with the side light source 112 being turned on in the samemanner as in the first example embodiment in accordance with the captureinstruction signal included in the control signal input from the imageprocessing apparatus 20 (step S106).

In the same manner as in the first example embodiment, image data of thefingerprint image captured by the image sensor 108 is transferred to theimage processing apparatus 20 via the communication cable 30 (stepS108). In the same manner as in the first example embodiment,predetermined image processing is performed on the image data of thefingerprint image transferred to the image processing apparatus 20.

Next, the CPU 202 of the image processing apparatus 20 determines basedon a criterion regarding the fingerprint image quality whether or notthe quality of the fingerprint image transferred from the fingerprintreading device 10 is good (step S206).

If the CPU 202 determines that the quality of the fingerprint image isgood (step S206, YES), the CPU 202 performs display, recording, or thelike of the fingerprint image in the same manner as in the first exampleembodiment (step S208).

In contrast, if the CPU 202 determines that the quality of thefingerprint image is not good (step S206, NO), the CPU 202 proceeds tostep S204, again outputs a control signal including a drive instructionsignal and a capture instruction signal described above, and againinputs the control signal to the fingerprint reading device 10. Notethat the CPU 202 may perform display or the like on the fingerprintimage determined to be not good in the same manner as in the firstexample embodiment.

The CPU 166 of the fingerprint reading device 10 to which the controlsignal is again input from the image processing apparatus 20 againperforms steps S104, S106, and S108. Thereby, the image data of thefingerprint image re-acquired in the fingerprint reading device 10 isagain transferred to the image processing apparatus 20. By step S104 ofdriving the sensor drive unit 114 being executed again, reduction orremoval of elastic deformation of a finger that is a factor of reductionin quality of a fingerprint image is attempted.

The CPU 202 of the image processing apparatus 20 to which the image dataof the fingerprint image is again transferred executes step S206 again.

In such a way, reading of the fingerprint performed by the fingerprintreading device 10 is repeated until a fingerprint image having a qualityof a predetermined value or higher is acquired.

As discussed above, in the present example embodiment, the imageprocessing apparatus 20 controls the fingerprint reading device 10 toautomatically read a fingerprint. Furthermore, in the present exampleembodiment, reading of a fingerprint performed by the fingerprintreading device 10 is repeated until a fingerprint image having a qualityof a predetermined value or higher is acquired based on a result of thefingerprint image quality determined by the image processing apparatus20. Therefore, according to the present example embodiment, a highquality fingerprint image can be efficiently acquired.

Further, while the case where the CPU 202 of the image processingapparatus 20 functions as the determination unit and the control unitthat control the operation of the fingerprint reading device 10 toautomate reading of a fingerprint performed by the fingerprint readingdevice 10 has been described above, the example embodiment is notlimited thereto. For example, the CPU 166 of the control circuit 116 ofthe fingerprint reading device 10 may function as the whole or a part ofthe determination unit and the control unit that automate reading of afingerprint performed by the fingerprint reading device 10 in a similarmanner to the CPU 202 of the image processing apparatus 20 describedabove.

Further, while the case where reading of a fingerprint is automated inthe first example embodiment has been described above, reading of afingerprint can be automated in the second to seventh exampleembodiments in the same manner as described above.

Another Example Embodiment

According to another example embodiment, the fingerprint reading devicedescribed in each of the above example embodiments may be configured asillustrated in FIG. 23 . FIG. 23 is a block diagram illustrating afunction configuration of the fingerprint reading device according toanother example embodiment.

As illustrated in FIG. 23 , a fingerprint reading device 8000 accordingto another example embodiment has a placement portion 8002 on which afinger is placed and a reading face 8004 with which the finger placed onthe placement portion 8002 contacts. Further, the fingerprint readingdevice 8000 has a pair of light sources 8006 that are provided on theplacement portion 8002 and irradiate a finger placed on the placementportion 8002 with lights. Furthermore, the fingerprint reading device8000 has a reading unit 8008 that captures and reads a fingerprint of afinger in contact with the reading face 8004 in accordance with lightsscattered in the finger and emitted from the surface of the finger. Thepair of the light sources 8006 are provided on both ends of the sensorface 8004 that are opposed to each other in the width direction of theplacement portion 8002. Further, each of the pair of light sources 8006has a light guiding part 8010 formed in the front-rear direction of theplacement portion 8002. The light guiding part 8010 is formed so as toextend up to above the end of the reading face 8004.

According to the fingerprint reading device 8000 according to anotherexample embodiment, it is possible to suppress the position of a fingerwhose fingerprint is to be read from being shifted with respect to areading face.

Modified Example Embodiments

The present invention is not limited to the example embodimentsdescribed above, and various modifications are possible.

For example, while the case where the image sensor 108 that is a readingunit of an optical type that captures and reads a fingerprint is usedhas been described as an example in the above example embodiments, thereading unit is not limited thereto. As the reading unit that reads afingerprint, various types such as an electrostatic capacitor type, anelectric filed intensity type, or the like other than the optical typecan be used.

Further, while the case where the image sensor 108 is driven by thesensor drive unit 114 together with the sensor cover 110 including thesensor face 118 with which a finger comes into contact has beendescribed as an example in the above example embodiments, the inventionis not limited thereto. Any configuration is possible as long as atleast the sensor face 118 is driven as described in the exampleembodiments described above, and the image sensor 108 or other readingunits that can read a fingerprint of a finger in contact with the sensorface 118 located in the capturing position may be fixed at a positionseparated from the sensor face 118.

The whole or part of the example embodiments disclosed above can bedescribed as, but not limited to, the following supplementary notes.

(Supplementary Note 1)

A fingerprint reading device comprising:

-   -   a placement portion on which a finger is placed;    -   a reading face with which the finger placed on the placement        portion contacts;    -   a pair of light sources that are provided on the placement        portion and irradiate the finger placed on the placement portion        with lights; and    -   a reading unit that captures and reads a fingerprint of the        finger in contact with the reading face in accordance with        lights scattered in the finger and emitted from a surface of the        finger,    -   wherein the pair of light sources are provided on both ends of        the reading face that are opposed to each other in a width        direction of the placement portion and    -   have light guiding parts formed in a front-back direction of the        placement portion, respectively, and    -   wherein the light guiding parts are formed so as to extend up to        above the ends of the reading face.

(Supplementary Note 2)

The fingerprint reading device according to supplementary note 1,wherein the light guiding parts are configured to be able to support thefinger placed on the placement portion.

(Supplementary Note 3)

The fingerprint reading device according to supplementary note 1 or 2,wherein the pair of light sources are inclined inward above the readingface.

(Supplementary Note 4)

The fingerprint reading device according to any one of supplementarynotes 1 to 3,

-   -   wherein each of the pair of light sources has a plurality of        unit light sources arranged extending in the front-rear        direction of the placement portion, and    -   wherein each of the light guiding parts is formed to cover the        plurality of unit light sources.

(Supplementary Note 5)

The fingerprint reading device according to supplementary note 4,wherein each of the light guiding parts has

-   -   a protrusion part covering the plurality of unit light sources,        and    -   an edge part formed integrally with the protrusion part on the        reading face side of the protrusion part and having a lower        height in a perpendicular direction of the placement portion        than the protrusion part.

(Supplementary Note 6)

The fingerprint reading device according to supplementary note 5,wherein the edge part and a part of the protrusion part are located overthe end of the reading face.

(Supplementary Note 7)

The fingerprint reading device according to supplementary note 5,wherein a part of the edge part is located over the end of the readingface.

(Supplementary Note 8)

The fingerprint reading device according to any one of supplementarynotes 5 to 7,

-   -   wherein a width of the edge part located over the end of the        reading face is wider toward a front side of the placement        portion.

(Supplementary Note 9)

The fingerprint reading device according to any one of supplementarynotes 5 to 7,

-   -   wherein the edge part of the light guiding part for one of the        pair of light sources and the edge part of the light guiding        part for the other of the pair of light sources are formed to be        continuous to each other above the reading face, and    -   wherein an opening that exposes the reading face is formed in        the edge parts.

(Supplementary Note 10)

The fingerprint reading device according to any one of supplementarynotes 1 to 9 further comprising a light shielding part formed on anunderside of the light guiding parts in a portion located on the ends ofthe reading face.

While the present invention has been described above with reference tothe example embodiments, the present invention is not limited to theexample embodiments described above. Various changes that can beappreciated by those skilled in the art within the scope of the presentinvention may be applied to the configuration or the detail of thepresent invention.

REFERENCE SIGNS LIST

-   -   1 fingerprint reading system    -   10, 2010, 3010, 4010, 5010, 6010, 7010, 8000 fingerprint reading        device    -   20 image processing apparatus

The invention claimed is:
 1. A fingerprint reading device comprising: aplacement portion on which a finger of a newborn is to be placed; alight source; a light guiding part that extends in a direction where theplacement portion extends and guides light from the light source; animaging sensor that captures an image of the finger of the newborn; asensor driver; and a processor configured to execute computer programinstructions to implement: controlling the sensor driver to move theimaging sensor from a position away from the finger to a position wherethe imaging sensor touches the finger.
 2. The fingerprint reading deviceaccording to claim 1, wherein the width of the light guiding part iswider on a tip side of the finger than on a base side of the finger. 3.The fingerprint reading device according to claim 2, wherein the widthof the light guiding part becomes wider as a position thereof goes fromthe tip side of the finger to the base side of the finger.
 4. Thefingerprint reading device according to claim 1, wherein the lightguiding part extends over the imaging sensor so as to have an openingexposing the imaging sensor, and wherein the width of the light guidingpart becomes wider as a position thereof goes to a base side of thefinger on the base side of the finger within the direction where lightguiding part extends.
 5. The fingerprint reading device according toclaim 4, wherein the opening has an ellipse shape.
 6. The fingerprintreading device according to claim 1, wherein the light guide portion hasa convex surface in a downward direction of the placement portion, on aside of the imaging sensor.
 7. The fingerprint reading device accordingto claim 1, further comprising a holding portion, wherein the directionin which the placement portion extends is inclined with respect to adirection in which the holding portion extends.